NEW YORK -- An on-duty New York City police officer was shot and critically injured Saturday evening and a search was underway for possible suspects, police said.

Dozens of police officers, marked and unmarked cars, emergency service unit trucks and police helicopters flooded the scene in the Queens Village neighbourhood, and officers could be seen searching house-by-house, looking in backyards, under cars and walking on top of roofs with their flashlights.

No arrests have been announced.

It wasn't immediately clear how the officer, who was not immediately identified, was rushed to Jamaica Hospital Medical Center in Queens. An ambulance called to the scene at 6:15 p.m. Saturday arrived to a report of the shooting, but the officer had already been rushed to the hospital, a fire department spokesman said.

Mayor Bill de Blasio was at the hospital, City Hall officials said.

Neighbours near the scene of the shooting were surprised by the violence and described the area as quiet and safe.

"You walk down the street, no trouble," said Sandreaus Adam, 52. "This is not a neighbourhood where you're just going to hear shots."

The shooting, the fifth of an on-duty officer in as many months in New York, comes after two NYPD officers were shot and killed in Brooklyn.

Officers Wenjian Liu, 32, and Rafael Ramos, 40, were shot at close range as they were sitting in their patrol car Dec. 20 in Brooklyn. The suspect, 28-year-old Ismaaiyl Brinsley, then ran into a nearby subway station and fatally shot himself.

Before the ambush, Brinsley posted on an Instagram account that he was planning to shoot two "pigs" in retaliation for Garner's death.

On Jan. 5, two plainclothes officers who were part of an anti-crime unit in the Bronx were shot and wounded. Each officer survived two gunshot wounds.