Police said the man holed up in a building on Main Street in Branford, a New Haven suburb. One person was reported injured.
The suspect was barricaded near Cherry Hill Road, and people were urged to avoid the area after the man reportedly fired shots at both officers and pedestrians at a shopping plaza.
Authorities say they received a report of shots fined in the area just after noon, and responding officers encountered heavy gunfire coming from the upper floors of a business/apartment building.
Additional 911 calls reported a gunshot victim nearby. This victim was later transported to the hospital with reported non-life threatening injuries.
Officers continued to face heavy gunfire and were pinned down until armored BearCat vehicles arrived.
More than four hours after the gunfire began, Branford police said on their Facebook page they were continuing "to work towards a peaceful resolution" and asked people to stay away, saying the area still wasn't safe.
Witnesses inside a nearby laundromat told sister station WTNH News 8 that the man was barricaded inside a hair salon and was opening fire onto police officers.
Other witnesses told News 8 the gunman was barricaded inside hair salon, with view of shopping plaza, where customers were taking cover.
They say the gunman fired towards the plaza and towards police, and a neighbor described hearing rapid gunfire.
Witnesses told News 8 they saw people running in the street, and that police are urging everyone in the area to take cover.
Several nearby businesses and homes were evacuated, and a ramp of Interstate 95 was closed.
Officers from several surrounding towns joined Branford and state police in responding to the scene.
(The Associated Press contributed to this report.)
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