An investigation is underway Wednesday after an arrest in upper Manhattan is caught on camera showing police officers beating a man with batons, raising questions if the incident constituted excessive police force.

It happened Tuesday afternoon near the intersection of 169th Street and Broadway in Washington Heights.

The video appears to show the two men — whom sources identified as 36-year-old Aaron Grissom and 37-year-old Sidney Williams — squaring up with the officers before the officers pulled out their expandable metal batons, known as ASPs. The two officers then hit Grissom with their batons.

Multiple plainclothes officers then join the uniformed officers in chasing down Williams near a car. The officers appear to try to restrain the man while he was down on the floor while the uniformed officers beat him with their batons. A plainclothes officer is also seen kicking Williams.

At one point in the video — after the man got up, struggled with officers, and appeared to swing at one of them before he was forced back to the ground — an officer hit him with his baton a few more times while the man was face down on the ground.

One witness can be heard in the video saying the street was stained with the blood of one of the men.

The police union, the Patrolmen's Benevolent Association, fired back at those, including some elected officials, who called it excessive force. Union officials said the two men, not the officers, used excessive force by swinging at the officers.

The union said police were called to the scene because the Grissom and Williams made a commotion in the nearby 168th Street subway station. According to the union, when the officers told the men to get on the floor, they did not comply.

"What the video doesn't show is that these perps — one of whom has been previously arrested for assaulting a police officer — threw a haymaker at the cops once they got above ground, necessitating the use of force to bring them into custody," said Pat Lynch, the president of the union, the Patrolmen's Benevolent Association.

Mayor Bill de Blasio and the city police department said an investigation is ongoing.

"The individuals involved were creating a real problem for neighborhood residents," the mayor said at an unrelated news conference Wednesday. "I don't have all the facts yet, I'm waiting to get them. But I want to emphasize: Any time an officer tells someone they're going to be put under arrest, it is the obligation of that individual to comply with the officer's order and not resist."

Sources said both of the uniformed officers were injured and later treated and released.

According to sources, Grissom and Williams have prior criminal histories, including assaults on police officers. They have been charged with Felony Assault on a Police Officer, Resisting Arrest, Menacing, Disorderly Conduct and Loitering, sources said.

According to sources, Grissom and Williams were arrested together in December for a similar incident with police officers at the same station. They were also treated and released from the hospital, sources said.

Police sources say in a 2017 Facebook post that two men appeared in, Sidney Williams bragged about fighting with cops.

"Ask the 25th precinct about me, the 67th, 73rd, 69th in Canarsie, they know me," Williams is heard saying in the video. "They don't like me, but they can't touch me because they get hurt and I get paid. I got three lawsuits and working on number four. These hands work." 

It is not confirmed if the police officers wore body cameras.