Tens of thousands of uniformed police officers from across the US were expected to attend the funeral on Sunday of the second New York Police Department officer fatally shot with his partner in their patrol car two weeks ago.

Buddhist monks will lead a Chinese ceremony for Officer WenjianLiu, followed by a traditional police ceremony with eulogies led by a chaplain. The funeral follows a somber wake the day before as mourners waited in line, stretching for blocks on a cold, rainy day to pay their respects.

Liu, 32, had served as a policeman for seven years and was married just two months before he was killed with his partner, Officer Rafael Ramos, on Dec20.Ramos' funeral was held a week ago.

"This is a really tragic story," Governor Andrew Cuomo said after the wake.

"This is really pointless. It had nothing to do with them," he said of Liu and Ramos." They did nothing wrong....It was pure and random-hatred."

Disturbed loner

The shooter, Ismaaiyl Brinsley, killed himself shortly after the brazen daytime ambush on a Brooklyn street.

Investigators said Brinsley was an emotionally disturbed loner who had made references online to the killings this summer of unarmed men at the hands of white police officers, "wings on pigs".

The deaths have strained an already tense relationship between city police unions and Mayor Bill de Blasio, whom union leaders said contributed to an environment that allowed the killings by supporting protests following the deaths of Eric Garner on Staten Island and Michael Brown in Ferguson, Missouri.

The head of the rank-and-file police union, which is negotiating a contract with the city, turned his back on the mayor at a hospital the day of the killings. The act was imitated by hundreds of officers standing outside Ramos' funeral who turned their backs toward a giant TV screen as de Blasio's remarks were being broadcast.

AP - Xinhua