NEW YORK (AP) -- The New York Police Department was searching Thursday for an unidentified gunman wanted in the shooting of a uniformed officer whose life was saved by his Kevlar vest.

A swarm of officers searched four apartments at a 900-resident Manhattan public housing project that was the scene of the shootout early Thursday. The manhunt also involved search dogs and helicopters, NYPD spokesman Paul Browne said. There were no arrests.

Officer Brian Groves was the ninth NYPD officer shot in the line of duty this year. Absent his vest, Groves could have become the first fatality, officials said.

Police Commissioner Raymond Kelly said that "by the grace of God and Kevlar" the lead bullet was lodged in Groves’ vest at the sternum, just by his heart’s right ventricle.

Groves, 30, and his partner were patrolling the housing project on the Lower East Side at about 3:40 a.m. when they came across a man in a stairwell with a gun protruding from his waistband, police said.

During a foot pursuit, the suspect fired at Groves from a distance of only eight feet, police said. The patrolman returned fired and continued pursuing the gunman before he fell, telling his partner, "I think I’ve been hit."

The suspect escaped. It was unclear whether he’d been injured by the exchange of gunfire.

Kelly and Mayor Michael Bloomberg visited Groves on Thursday morning at Bellevue Hospital, where doctors examined the officer to make sure his heart hadn’t bruised as a result of the trauma.

"I think it’s fair to say only pure luck and our prayers prevented this situation from becoming a tragedy," Bloomberg told reporters.

Groves and his wife, Nicole, have two children, including a newborn. They live in Patchogue on Long Island. He has worked in the police department’s housing bureau since 2005.

The group COP SHOT offered a $10,000 cash reward for information leading to a conviction.

Meanwhile, a transit officer was expected to be released from the hospital after he was stabbed in the eye Wednesday at a Long Island Rail Road station in Queens. Metropolitan Transportation Authority Officer John Barnett shot the suspect to death.

It remained unclear whether Barnett, who underwent more than four hours of surgery, would lose vision in his left eye. The surgeon described the wound as devastating, according to MTA spokeswoman Marjorie Anders.