2 NYPD officers shot and killed in their police car

Two New York Police Department officers were shot and killed at point blank range in their patrol car here by a man who later shot himself at a nearby subway station, an attack described as an "assassination".

The officers were identified as Wenjin Liu, a seven-year veteran of the NYPD, and Raphael Ramos, who joined the force two years ago.

The gunman was identified as 28-year-old Ismaaiyl Brinsley who had driven from Baltimore and authorities said had written in social media posts that he planned to kill police officers in the wake of the deaths of Eric Garner and Michael Brown by police officers.

"Our city is in mourning. Our hearts are heavy," Bill de Blasio said in a press conference.

"Although we are still learning the details, it is clear that this was an assassination," he said, adding that when a police officer is murdered, it "tears at the foundation of our society."

"Our entire city was attacked by this heinous individual," the mayor said.

NY Police Commissioner William Bratton said Ramos and Liu were among New York's "finest" police officers and "were shot and killed with no warning or provocation.

"While sitting in a marked police car, both were ambushed and murdered. Both officers paid the ultimate sacrifice today while protecting the communities they served," Bratton said.

Authorities said Brinsley walked up to the police car in which the two officers were sitting and "took a shooting stance" outside their vehicle in the Bedford-Stuyvesant section of Brooklyn.

He shot through the passenger side window on the officers' heads and upper bodies in an attack so sudden that the officers could not even draw their weapons.

He then ran to a nearby subway station and committed suicide by shooting himself.

A semi-automatic handgun was recovered at the scene. "Officer Ramos and Officer Liu never had the opportunity to draw their weapons," Bratton said. "They may never have had the chance to see their murderer."

Bratton and de Blasio met with the officers' families last evening.

Wu was married just two months ago and Ramos has a 13-year old son who "couldn't comprehend what had happened to his father," the mayor said.

Bratton said Brinsley had shot and seriously wounded his ex-girlfriend last morning in Baltimore and made posts from her Instagram account that were "very anti-police."

CBS news quoted a police source as saying that Brinsley had posted a photo of a handgun on Instagram a few hours before the shooting.

"I'm Putting Wings On Pigs Today," the post said.

"They Take 1 Of Ours. Let's Take 2 Of Theirs. #ShootThePolice #RIPErivGardner (sic) #RIPMikeBrown This May Be My Final Post. I'm Putting Pigs In A Blanket," (sic).

The shooting of the police officers comes days after protests had erupted across the US over the deaths by black men Garner and Brown at the hands of the police.

The police officers responsible for the two deaths were not criminally charged by federal grand juries, sparking wide-spread protests and anger in the US, particularly in the African-American community.

An unarmed Garner was stopped by police for selling loose, untaxed cigarettes and was put in a chokehold as he was getting arrested.

His last words, "I can't breathe" became a slogan as communities protested police brutality and policies.

Garner's death came closely after a Missouri grand jury decided not to indict a white officer in the fatal shooting of Brown, an unarmed black 18-year-old.

According to the Baltimore County Police, Brinsley had faxed a warning flier to the NYPD, but it was not received until around the same time as the shooting occurred.

Attorney General Eric Holder condemned the "senseless shooting," saying "this was an unspeakable act of barbarism, and I was deeply saddened to hear of the loss of these two brave officers in the line of duty."

Holder said the "cowardly attack" underscores the dangers that are routinely faced by those who protect and serve citizens.

He said the country must always honor the valor and sacrifices of all law enforcement officers with a steadfast commitment to keeping them safe.

"This means forging closer bonds between officers and the communities they serve, so that public safety is not a cause that is served by a courageous few, but a promise that's fulfilled by police officials and citizens working side by side," Holder said.

Civil rights leader Rev. Al Sharpton, who has helped organize some of the demonstrations against police brutality, also released a statement denouncing the killings.

"Any use of the names of Eric Garner and Michael Brown, in connection with any violence or killing of police, is reprehensible and against the pursuit of justice in both cases," Sharpton said.

"We have stressed at every rally and march that anyone engaged in any violence is an enemy to the pursuit of justice for Eric Garner and Michael Brown... The Garner family and I have always stressed that we do not believe that all police are bad, in fact we have stressed that most police are not bad."