UNION SQUARE (WABC) --Police in Manhattan continue to search for a man who is randomly attacking people with a hammer, and they have released a photo of the suspect.
Authorities believe the man attacked four people and threatened a fifth.
The were two separate attacks Monday night on West 18th Street and West 17th Street near Union Square Park.
Neither victim, a 28-year-old woman and a 33-year-old woman, knew the suspect who assaulted them. They were taken to an area hospital with non-life threatening injuries.
Around 7:30 p.m., the 28-year-old was sitting in the park when a man took out a hammer from a bag and struck her head. She was taken to Lenox Hill Hospital.
About 10 minutes later, the other woman, walking west on West 17th Street, was approached by the suspect from behind and struck in the back of the head.
She was taken to Lenox Hill Hospital in stable condition. The suspect fled in an unknown direction. Both victims were treated and released.
In another incident on Monday at 1:45 p.m. at Sixth Avenue and West 35th Street, a 20-year-old man said he was hit with a hammer. He was not injured, and the suspect fled the scene. According to the NYPD, the incident appears to be linked to the other two.
And a 34-year-old woman said she was punched in the head by the man on East 26th Street and Madison Avenue at 5:10 p.m. Monday.
Detectives also spoke to a man who said he was threatened by a man with a hammer in Madison Square Park Monday afternoon. He was not struck.
Authorities are combing through all previously reported attacks involving hammers to see if there are any links, and they are putting together a timeline of sightings that starts in Midtown at midday and extends to Union Square in the early evening.
The suspect in the Union Square incident is described as in his 30s, medium build, wearing a black waist length jacket, dark-colored baseball hat, dark jeans, black sneakers, and wearing a black backpack.
Anyone with information is asked to call 800-577-TIPS.