New York cop in serious condition after hatchet attack

 A rookie New York police officer remained in hospital in a serious condition on Friday after being attacked by a man with a hatchet who was then shot dead by officers, AFP reports.

Police are investigating the motive but New York state governor Andrew Cuomo said he had no definitive information on suggestions that the attack Thursday was terror-related.

"There is nothing we know of at this time that would indicate that were the case," police commissioner Bill Bratton said.

He acknowledged that terror concerns were heightened after two deadly attacks in Canada this week.

The 25-year-old New York police officer, who was patrolling on foot in the city's borough of Queens with three other rookie officers, was seriously injured in the back of his head.

Another officer was hit in the arm. The other officers shot and killed the attacker, according to Bratton.

US media identified the attacker as Zale Thompson, 32. The New York Post reported that he had recently converted to Islam.

The SITE monitoring group said that he displayed "extremist leanings" in an array of statements on YouTube and Facebook.

SITE, which monitors radical Muslim groups, said Thompson described "jihad as a justifiable response to the oppression of the 'Zionists and the Crusaders'" in a comment posted to a pro-Islamic State video on September 13, 2014.

A 29-year-old bystander was also accidentally hit by a bullet in the lower back and taken to hospital, Bratton said.

Queens residents said that they were disturbed by the attack.

"A thing like that isn't supposed to happen, children can be on the streets," said a woman who gave her name as Helena.

"Anyone could get caught in this incident and I don't think that's right, it's not right," she told AFP.