A group of teens, including one wielding a hammer, beat up a 67-year-old man after a confrontation that started on a Brooklyn bus, according to video and the NYPD.

Footage of the incident on the B6 bus in East Flatbush obtained by The Post shows one of the group yelling at the older man as a woman tries to keep them separated.

“Get off the bus!” the woman tells them repeatedly in the video. The older man begins to walk away before turning back and walking toward the door.

One of the kids then throws something at the man, who darts off the bus only to find himself facing off with one of the teens, who pulls out a hammer.

The man is soon surrounded by the group, who all start taking swings at him, including the boy with the hammer.

“You’re gonna kill him!” one woman on the bus screams, as others can be heard crying in the background. The clip cuts off right as one of the assailants moves to kick the senior citizen from behind as he reels on the ground.

The incident at Glenwood Road and Albany Avenue occurred around 2 p.m. Monday, according to an NYPD spokeswoman.

The suspects are unknown and at large, police said. The elder victim, who appeared to be in a security uniform, suffered a cut to the head from the hammer strike.

MTA officials referred all questions to the police.

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