New York police officer Brian Moore shot in the head after stopping to question man in Queens

The 25-year-old is in a critical condition in hospital

Photo released by the New York City Police Department shows officer Brian Moore, 25 (AP)

A police officer is in critical condition after he was shot in the head while trying to question a man in New York.

Brian Moore, 25, has reportedly been placed in a medically induced coma after undergoing surgery at a nearby hospital in the borough of Queens.

Police said Moore was dressed in plainclothes when he and another officer stopped to question a man at about 6.15pm.

New York Police Commissioner William Bratton told reporters the officers stopped a man after observing him adjusting an object at his waist – at which point the suspect “removed a firearm from his waistband and ... fired several times into the vehicle”.

Mayor Bill de Blasio (second from left) and Police Commissioner William Bratton (centre) speak at a news conference Saturday night, May 2, 2015 (AP)

Bratton said the officers were both “still seated in the vehicle and did not have an opportunity to get out or return fire”.

Around 90 minutes after the incident police arrested 35-year-old Demetrius Blackwell, who had recently been paroled after serving seven years in prison for attempted murder, in a house not far from the crime scene.

No weapon was found and Blackwell has not been charged, police said.

Officials said the incident was the fifth shooting of a New York police officer in as many months, and New York Mayor Bill de Blasio called it “a reminder of the dangers all of our officers face every single day”.

20 December 2014: The scene where two New York City police officers were killed as they sat in their marked police car on a Brooklyn street corner (Spencer Platt/Getty Images)

De Blasio said Moore, who local media reported had been shot in the face, was “very, very seriously injured”. He said he came from a police family and had served with distinction.

The shooting comes at a time of increased national focus both on the use of force by law enforcement officers and the dangers of police work. On Friday, six officers were charged in the death of a Baltimore man who was injured while in police custody.

De Blasio's relations with New York City police fell sharply after two city officers were shot and killed in December as they sat in their patrol car, in what officials said was a targeted attack.

Hundreds of officers turned their backs when de Blasio delivered a eulogy at one of the officer's funerals, angry at what they saw as his failure to support them during a wave of anti-police protests in the city late last year.

Additional reporting by agencies