Officials said they found bricks and rocks hidden in strategic places on street corners in Brooklyn and Queens.
The boxes were not in the vicinity of any protests, but the NYPD believes they were to be picked up to be used at a future protest.
Police Commissioner Dermot Shea said bricks were recently stolen from a construction site in Manhattan, and police are looking into if that burglary is connected.
He also revealed that "seemingly innocuous plastic bottles" thrown at police during protests "are often filled with cement."
Along with being thrown at officers, protesters are also throwing the bottles at police cruisers, causing large amounts of damage.
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Protesters march in lower Manhattan, Saturday, June 6, 2020, in New York.AP
Protesters march in lower Manhattan, Saturday, June 6, 2020, in New York.AP
A group of protesters take a knee while marching in lower Manhattan, Saturday, June 6, 2020, in New York.AP
Protesters march in lower Manhattan, Saturday, June 6, 2020, in New York.AP
Protesters and activists walk across the Brooklyn Bridge, Saturday, June 6, 2020, in New York.AP
Demonstrators move along W. 34th Street Saturday, June 6, 2020, in New York.AP
Activists move along Seventh Avenue, Saturday, June 6, 2020, in New YorkAP
Protesters and activists walk across the Brooklyn Bridge, Saturday, June 6, 2020, in New York.AP
A group of protesters take a knee while marching in lower Manhattan, Saturday, June 6, 2020, in New York.AP
A man holds a photograph of Breonna Taylor on her birthday as he kneels with other protesters on Atlantic Avenue during a solidarity rally for George Floyd on Atlantic AvenueAP
Police officers stop protesters from marching during a solidarity rally for George Floyd, Friday, June 5, 2020, in the Brooklyn borough of New York.AP
A man holds a photograph of Breonna Taylor on her birthday as he kneels with other protesters on Atlantic Avenue during a solidarity rally for George Floyd on Atlantic AvenueAP
Protesters gather on Atlantic Avenue during a solidarity rally for George Floyd, Friday, June 5, 2020, in BrooklynAP
Courtney Taylor Mesidor smiles at a police officer as he takes her photo upon arresting her for breaking a curfew during a solidarity rallyAP
Protesters are arrested by New York Police Department officers on Park Avenue after violating curfew, Friday, June 5, 2020, in New York.AP
Protesters link arms when their march is stopped by police officers at Grand Army Plaza during a solidarity rally for George Floyd, Friday, June 5, 2020, in BrooklynAP
Protesters link arms when their march is stopped by police officers at Grand Army Plaza during a solidarity rally for George Floyd, Friday, June 5, 2020, in BrooklynAP
Medical professionals join a protest rally at Union Square, Friday, June 5, 2020, in the Manhattan borough of New York.AP
Medical professionals join a protest rally at Union Square, Friday, June 5, 2020, in the Manhattan borough of New York.AP
Protesters gather in the rain for a rally at Union Square, Friday, June 5, 2020, in the Manhattan borough of New York.AP
Protesters gather during a solidarity rally for George Floyd, Thursday, June 4, 2020, in the BrooklynAP
Protesters who were arrested by police for breaking a curfew during a solidarity rally, sit on a sidewalk as they wait to be taken away in a vanAP
Protesters who were arrested by police for breaking a curfew during a solidarity rally calling for justice over the death of George Floyd on Thursday, June 4, 2020, in New York.AP
A protester is arrested on Fifth Avenue by NYPD officers during a march, Thursday, June 4, 2020, in the Manhattan borough of New York.AP
A protester who was arrested for breaking a curfew during a rally calling for justice over the death of George Floyd looks out from a police van on Thursday, June 4, 2020AP
Terrence Floyd, center, brother of the deceased George Floyd, marches onto the Brooklyn Bridge after a rally at Cadman Plaza Park, Thursday, June 4, 2020, in BrooklynAP
Protesters break curfew and march, Thursday, June 4, 2020, in the Chelsea neighborhood of New York.AP
Protesters march past a kiosk displaying Trayvon Martin's name during a solidarity rally for George Floyd, Thursday, June 4, 2020, in the Brooklyn borough of New York.AP
New York Police Department officers stand in formation after arresting multiple protesters marching after curfew on Fifth Avenue, Thursday, June 4, 2020, in New York.AP
A healthcare professional riding a bus, left, greets protesters as they break curfew and march along 34th Street, Thursday, June 4, 2020, in the Manhattan borough of New York.AP
Protesters march down a residential street during a solidarity rally calling for justice over the death of George Floyd, Thursday, June 4, 2020, in BrooklynAP
Protesters march on the Brooklyn Bridge after a rally in Cadman Plaza Park, Thursday, June 4, 2020, in New York.AP
New Yorkers gather for a memorial service for George Floyd at Cadman Plaza Park in the Brooklyn borough of New York, on Thursday, June 4, 2020.AP
The brother of George Floyd, Terrence Floyd speaks to a crowd during a rally at Cadman Plaza Park, on Thursday, June 4, 2020, in the Brooklyn borough of New York.AP
New York Police Department officers stand in formation after arresting multiple protesters marching after curfew on Fifth Avenue, Thursday, June 4, 2020, in New York.AP
Protesters march on the Brooklyn Bridge after a rally in Cadman Plaza Park, Thursday, June 4, 2020, in New York.AP
A protester waves an American flag with a message that reads "CAN'T BREATHE" during a memorial for George Floyd at Cadman Plaza Park in the Brooklyn borough of New YorkAP
Protesters march down a residential street during a solidarity rally calling for justice over the death of George Floyd, Thursday, June 4, 2020, in BrooklynAP
Protesters march on the Brooklyn Bridge after a rally in Cadman Plaza Park, Thursday, June 4, 2020, in New York.AP
Protesters take a knee on Flatbush Avenue in front of New York City police officers during a solidarity rally for George Floyd, Thursday, June 4, 2020, in BrooklynAP
New York Police Department officers watch protesters march during a solidarity rally for George Floyd, Thursday, June 4, 2020, in the Brooklyn borough of New York.AP
Demonstrators march on the Brooklyn Bridge after a memorial service for George Floyd, on Thursday, June 4, 2020, in New York.AP
Health care workers at Brooklyn's Kings County Hospital show their solidarity with the Black Lives Matter movement, Thursday, June 4, 2020 in New YorkAP
New York City police officers arrest a protester after a rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in BrooklynAP
Protesters march Wednesday, June 3, 2020, in the Brooklyn borough of New York, as part of a solidarity rally calling for justice over the death of George Floyd.AP
Protesters sit in a bus after being arrested during a rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in the Brooklyn borough of New York.AP
New York City police officers gather early Thursday, near the site of shooting Wednesday night in the Brooklyn. The police department says two officers were woundedAP
Protesters sit during a solidarity rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in New York.AP
Protesters gather during a solidarity rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in BrooklynAP
Protesters sit together with their fists in the air during a solidarity rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in New York.AP
Protesters march through Times Square during a solidarity rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in New York.AP
Protesters kneel in front of New York City Police Department officers before being arrested for violating curfew beside the iconic Plaza Hotel on 59th StreetAP
Police arrest protesters as they march through the streets of Manhattan, New York, Wednesday, June 3, 2020.AP
Protesters confront New York Police officers as part of a solidarity rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in BrooklynAP
A protester is arrested for violating curfew near the Plaza Hotel on Wednesday, June 3, 2020, in the Manhattan borough of New York.AP
Protesters confront New York Police officers as part of a solidarity rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in BrooklynAP
Protesters rally at Washington Square Park before marching, Wednesday, June 3, 2020, in the Manhattan borough of New York.AP
Protesters are seated on a bus after being arrested at a rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in BrooklynAP
Protesters march as part of a solidarity rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in BrooklynAP
New York City police officers watch protesters calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in BrooklynAP
Protesters rally near Gracie Mansion, the mayor's residence, in New York, Wednesday, June 3, 2020.AP
Protesters raise their fists and cheer as they march up Sixth Avenue on their way towards Columbus Cirle, Wednesday, June 3, 2020, in ManhattanAP
Protesters walk up to police with their hands in the air before they are arrested after a curfew went into effect, Wednesday, June 3, 2020, in ManhattanAP
New York City police officers arrest protesters following a rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in BrooklynAP
A protester is arrested for violating curfew near the Plaza Hotel on Wednesday, June 3, 2020, in the Manhattan borough of New York.AP
Protesters take a knee beside the Port Authority Bus Terminal during a march Wednesday, June 3, 2020, in ManhattanAP
Police arrest protesters for breaking an imposed curfew by marching through Manhattan Wednesday, June 3, 2020AP
Security personnel with dogs stand guard outside Saks Fifth Avenue, Wednesday, June 3, 2020, in the Manhattan borough of New York.AP
Associated Press videojournalist Robert Bumsted reminds a police officer that the press are considered essential workers" and are allowed to be on the streets despite a curfewAP
Health workers take a knee in solidarity with protesters as they take part in a protest during a march for George Floyd, Tuesday, June 2, 2020, in New York.AP
Police line the streets of lower Manhattan during an imposed curfew near where protesters were arrested for refusing to leave during a solidarity rally.AP
Police take into custody a protester who declined to get off the streets during a curfew that had begun, Tuesday, June 2, 2020, in New York.AP
Protesters march through the streets of Manhattan, Tuesday, June 2, 2020, in New York.AP
NYPD Deputy Police Chief McCarthy greets protesters as they take part in a solidarity march for George Floyd, Tuesday, June 2, 2020, in New YorkAP
Police arrest a protester who fell to the ground while others move forward to make more arrests of protesters refusing to get off the streets during an imposed curfewAP
People pass "Black Lives Matter" graffiti as they walk along Broadway in lower Manhattan, Tuesday, June 2, 2020, in New York.AP
Police ride their scooters through the East Village neighborhood of New York, patrolling the streets during an imposed curfew on Tuesday, June 2, 2020, in New York.AP
A protester raises her hands as police start to arrest demonstrators refusing to get off the streets during an imposed curfew while marching in a solidarity rallyAP
Police cycle in to arrest protesters refusing to get off the streets during an imposed curfew while marching in a solidarity rallyAP
Protesters reenact the scene where George Floyd was restrained by police while marching in a solidarity rally calling for justice over the death of George FloydAP
Police arrest a group of people after curfew in New York, Tuesday, June 2, 2020. New York City extended an 8 p.m. curfew all weekAP
A person leans on a Link NYC Kiosk showing George Floyd's name after rally for him, Tuesday, June 2, 2020, in BrooklynAP
A protester and a police officer shake hands in the middle of a standoff during a solidarity rally calling for justice over the death of George Floyd Tuesday, in New York.AP
New York Police Officers pass the Barclays Center after protesters departed a rally for George Floyd, Tuesday, June 2, 2020, in BrooklynAP
Police block protesters from exiting the Manhattan Bridge in New York, Tuesday, June 2, 2020. New York City extended an 8 p.m. curfew all weekAP
A 'Black Lives Matter' flag flies near Barclays Center after protesters leave a rally for George Floyd, Tuesday, June 2, 2020, in BrooklynAP
Protesters kneel in Times Square in New York, Tuesday, June 2, 2020. New York City extended an 8 p.m. curfew all weekAP
New York police block protesters and activists crossing the Manhattan Bridge from entering the borough Tuesday, June 2, 2020.AP
Natalie Colon, left, an employee with Paradise Pawn, is helped by community volunteer Jode Santana to clean up broken glass windows, Tuesday, June 2, 2020, in the BronxAP
Protesters gather at Foley Square on Tuesday, June 2, 2020, in New YorkAP
Protesters raise their fist in front of Gracie Mansion, the official residence of the New York mayor, during a protest Tuesday, June 2, 2020AP
AP
Protesters march through midtown as part of a demonstration Tuesday, June 2, 2020, in New York,AP
Police arrest a man during a solidarity rally calling for justice over the death of George Floyd Monday, June 1, 2020, in the Brooklyn borough of New York.AP
New York police officers park their vehicles outside Macy's store after it was broken into hours after a solidarity rallyAP
Protesters march during a solidarity rally for George Floyd, Monday, June 1, 2020, in the Brooklyn borough of New York.AP
Protesters march during a solidarity rally for George Floyd, Monday, June 1, 2020, in the Brooklyn borough of New York.AP
Police officers surround a group of people at Radio City Music Hall before arresting them in New York, Monday, June 1, 2020.AP
Protesters march during a solidarity rally for George Floyd, Monday, June 1, 2020, in the Brooklyn borough of New York.AP
Police officers detain a person Monday, June 1, 2020, in New York.AP
New York Police officers gather on 42nd Street, Monday, June 1, 2020, in New YorkAP
In this Monday, June 1, 2020, photo, mannequins lay on the floor of a damaged outdoor clothing store in midtown ManhattanAP
People being chased by police run past pedestrians near Union Square, Monday, June 1, 2020, in New York.AP
Protesters march across the Brooklyn Bridge as part of a solidarity rally calling for justice over the death of George Floyd Monday, June 1, 2020, in BrooklynAP
A person take a picture of a damaged storefront Monday, June 1, 2020, in New York.AP
Protesters march during a solidarity rally for George Floyd, Monday, June 1, 2020, in BrooklynAP
People take items from a store hours after a solidarity rally calling for justice over the death of George Floyd Monday, June 1, 2020, in New York.AP
A New York Police Department officer stands watch outside a Macy's store, Monday, June 1, 2020, in New York.AP
A person enters a store through a broken window Monday, June 1, 2020, in New York.AP
Police officers arrest a large group of people at Radio City Music Hall in New York, Monday, June 1, 2020.AP
The glass door of a souvenir shop is shattered as people broke into it hours after a solidarity rally calling for justice over the death of George Floyd Monday, June 1, 2020AP
Protesters march across the Brooklyn Bridge as part of a solidarity rally calling for justice over the death of George Floyd Monday, June 1, 2020, in BrooklynAP
New York police detain people Tuesday, June 2, 2020, about an hour past an 11 pm curfew that is being enforced following unrest in the wake of the death of George Floyd.AP
Chief of Department of the New York City Police, Terence Monahan, hugs an activist as protesters paused while walking in New York, Monday, June 1, 2020.AP
In this Monday, June 1, 2020, photo, shoes are seen through a hole in the damaged glass in the Chelsea neighborhood of ManhattanAP
People exit damaged stores after the glass was knocked out in the Chelsea neighborhood of New York, Monday, June 1, 2020.AP
Small pockets of fires burn in midtown Manhattan hours after a solidarity rally calling for justice over the death of George Floyd, Monday, June 1, 2020, in New York.AP
A person who was identified by others who came to his aid as a New York City police officer, second from right, is helped from the ground after being beaten in ChelseaAP
Police officers tackle a suspect trying to escape in New York, Monday, June 1, 2020.AP
Protesters walk across the Brooklyn Bridge in New York, Sunday, May 31, 2020.AP
Protesters march around a large sculpture of a globe in Flushing Meadows Corona Park in the Queens borough of New York, Sunday,AP
Police move to detain protesters as they march down a street during a solidarity rally for George Floyd, Sunday, May 31, 2020, in the Brooklyn borough of New York.AP
Police move to detain protesters as they march down a street during a solidarity rally for George Floyd, Sunday, May 31, 2020, in the Brooklyn borough of New York.AP
Protesters march down a street during a solidarity rally for George Floyd, Sunday, May 31, 2020, in the Brooklyn borough of New York.AP
Protesters start fires along the SoHo shopping district on Sunday, May 31, 2020, in New York.AP
Police form a line on Fifth Avenue outside Trump Tower on Sunday, May 31, 2020, in New York.AP
Activists march to the Brooklyn Bridge on Sunday, May 31, 2020, in New York.AP
Protesters walk on the roadway of the Brooklyn Bridge in New York, Sunday, May 31, 2020.AP
People break into a smoke shop in SoHo on Monday, June 1, 2020, in New York.AP
People break into a smoke shop in SoHo on Monday, June 1, 2020, in New York.AP
A protester runs as he is chased by police on Monday, June 1, 2020, in New York.AP
A man holds a U.S. flag upside down, a sign of distress, as protesters march down the street during a solidarity rally for George Floyd, Sunday, May 31, 2020, in BrooklynAP
A woman is arrested after being pulled out of a passenger seat for reckless driving as protesters take to the streets in SoHo on Sunday, May 31, 2020, in New York.AP
Police hold off protesters during a solidarity rally for George Floyd, Sunday, May 31, 2020,AP
Protesters march down a street during a solidarity rally for George Floyd, Sunday, May 31, 2020, in the Brooklyn borough of New York.AP
People carry things out of a smoke shop through a broken window in New York, Monday, June 1, 2020.AP
Activists march to the Brooklyn Bridge on Sunday, May 31, 2020, in New York.AP
Protesters march down a street during a solidarity rally for George Floyd, Sunday, May 31, 2020, in the Brooklyn borough of New York.AP
Police arrest a driver during ongoing looting in the SoHo shopping district on Sunday, May 31, 2020, in New York.AP
People run out of a smoke shop that they broke into as police arrive on the scene on Monday, June 1, 2020, in New York.AP
People run out of a smoke shop with smoking instruments after breaking in as police arrive on Monday, June 1, 2020, in New York.AP
People run out of a smoke shop with smoking instruments after breaking in as police arrive on Monday, June 1, 2020, in New York.AP
Protesters march down a street during a solidarity rally for George Floyd, Sunday, May 31, 2020, in the Brooklyn borough of New York.AP
Police officers confront protesters near New York's Union Square Saturday May 30, 2020, as they demonstrate against the the death of George FloydAP
A protester throws a traffic barrel at police during a protest in the Brooklyn borough of New York, Saturday, May 30, 2020.AP
Police officers pull a man off his bike to arrest him during a protest in the Brooklyn borough of New York, Saturday, May 30, 2020.AP
Police officers react as a firework is thrown in their midst during a protest in the Brooklyn borough of New York, Saturday, May 30, 2020.AP
Protesters hold their hands in the air in the Brooklyn borough of New York, Saturday, May 30, 2020.AP
Photographers take pictures of a burning police car in the Brooklyn borough of New York, Saturday, May 30, 2020.AP
Damage is seen at an Urban Outfitters store near New York's Union Square Sunday, May 31, 2020, after it was damaged in the midst of a protest highlighting the death of George FloydAP
Police scuffle with protesters in the Brooklyn borough of New York, Saturday, May 30, 2020.AP
Police in riot gear walk down a street during a protest in the Brooklyn borough of New York, Saturday, May 30, 2020.AP
New York Police officers use pepper spray on protesters during a demonstration Saturday, May 30, 2020, in the Brooklyn borough of New York.AP
A vehicle burns near New York's Union Square Saturday, May 30, 2020, as police confronted protesters in the death of George FloydAP
A vehicle burns near New York's Union Square Saturday May 30, 2020, as police confronted protesters in the death of George FloydAP
A vehicle burns near New York's Union Square Saturday, May 30, 2020, as police confronted protesters in the death of George FloydAP
New York Police officers restrain protesters during a demonstration, Saturday, May 30, 2020, in the Brooklyn borough of New York.AP
Police officers confront protesters near New York's Union Square, Saturday, May 30, 2020, during a demonstration against the the death of George FloydAP
Damage is seen at a bank near New York's Union Square Sunday, May 31, 2020, after it was damaged in the midst of a protest highlighting the the death of George FloydAP
A vehicle burns near New York's Union Square, Saturday, May 30, 2020, during a demonstration against the the death of George FloydAP
Police officers confront protesters near New York's Union Square Saturday May 30, 2020, as they demonstrate against the the death of George Floyd.AP
A vehicle, background, burns as police officers confront protesters near New York's Union Square, Saturday May 30, 2020AP
Police officers confront protesters near New York's Union Square Saturday May 30, 2020, as they demonstrate against the the death of George Floyd.AP
Police detain a protester during a solidarity rally for George Floyd, Saturday, May 30, 2020AP
Protesters march down the street as trash burns in the background during a solidarity rally for George Floyd, Saturday, May 30, 2020, in New York.AP
Police detain protesters as they march down the street during a solidarity rally for George Floyd, Saturday, May 30, 2020AP
Police officers confront protesters near New York's Union Square Saturday May 30, 2020, as they demonstrate against the the death of George Floyd.AP
Protesters march during a solidarity rally for George Floyd, Saturday, May 30, 2020, in New York. Demonstrators took to the streets of New York City to protest the death of FloydAP
Protesters rally at the Barclays Center over the death of George Floyd BrooklynAP
Protesters rally at the Barclays Center over the death of George Floyd BrooklynAP
Fire work on a New York police vehicle that was set on fire as Police Officers control the crowd near Fort Greene ParkAP
Police officers arrest protestors near Barclays Center after a rally over the death of George FloydAP
A young protestor is led away by an adult from approaching a police station to rally over the death of George FloydAP
Police try to contain protesters during a rally at the Barclays Center over the death of George FloydAP
Protesters stand near a burned New York City Police Department van in the Brooklyn borough of New York, Friday, May 29, 2020.AP
Police officers confront protesters in the street as they take a knee to demonstrate against the the death of George FloydAP
Police officers face off with protestors near Barclays Center after a rally over the death of George FloydAP
Police arrest protesters during a rally Friday, May 29, 2020, in the Brooklyn borough of New York, at the Barclays Center over the death of George FloydAP
Protesters rally at the Barclays Center over the death of George FloydAP
A police officer walks past a burning police vehicle on DeKalb Avenue in BrooklynAP
Police arrest protesters during a rally at the Barclays Center over the death of George FloydAP
A protester is arrested during a rally at the Barclays Center over the death of George FloydAP
Police officers block off DeKalb Avenue in the Brooklyn borough of New York as a police vehicle burns after protesters gathered at Barclays CenterAP
A Police vehicle burns after protesters rallied at Barclays Center over the death of George FloydAP
Police vehicles line the main roads after dispersing protestors near Barclays Center after a rally over the death of George FloydAP
Police officers help a colleague who was injured by protesters during a rally at the Barclays Center over the death of George FloydAP
A demonstrator is arrested as he protests against the the death of George FloydAP
Protesters demonstrate against the the death of George FloydAP
Protestors confront Police Officers near Barclays Center after a rally over the death of George FloydAP
Police officers, left, face off with protestors near the Barclays Center after a rally over the death of George FloydAP
Police and Court officers stand guard in front of Manhattan Criminal court as protesters demonstrate against the the death of George FloydAP
A protestor is arrested near Barclays Center after a rally over the death of George FloydAP
A protestor is arrested near Barclays Center after a rally over the death of George FloydAP
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