VIDEO: Cops investigate officer caught hitting teen suspect

A video making the rounds online on Friday that appears to show a teenager being roughed up by a plainclothes officer is under investigation, authorities said.

Footage captured on a Lower East Side street on Dec. 15 shows officers arresting at least two teens who police said Friday are suspected of assaulting an unidentified victim earlier in the day.

The YouTube video titled “Black Kids Matter” shows three officers restraining on teen when an unnamed police officer in blue jeans and a camo jacket comes up from behind and starts punching at the teen’s back.

NYPD’s Internal Affairs Bureau is investigating the officer and video in question.

Passersby watching the scene unfold shouted at the officer to “get off of him” and said that the boy was only 12 years old.

“This is not a war, this is a 12-year-old kid,” shouts one woman who in the video said she was a lawyer. “They’re animals right?”

But cops said the three suspects they eventually apprehended were all teenagers allegedly involved in a random gang attack about two blocks away from where they were arrested near East Broadway and Jefferson Street.

Officials said the cops responded to 207 Madison St. after receiving multiple 911 calls about a man being beat up with sticks and canes, shouting for help.

Police found the 20-year-old victim, who said he had been attacked by a group of teens who fled the scene. Paramedics took the man to Mount Sinai Beth Israel to be treated for a fractured jaw.

Officers canvassed the nearby area when they came across at least three teens identified as the assailants. On Friday morning, police said they had arrested a 17-year-old male and two 16-year-old males.

All were charged with gang assault and criminal possession of a weapon. One of the 16 year old also faces resisting arrest charges, and police said was previously arrested for robbery and gang assault.