Philadelphia police have released video of an assault last month in which a teenager was knocked unconscious with a broken jaw. Police are offering a $1,000 reward for the arrest and conviction of those responsible.

The attack happened about 12:45 a.m. Nov. 16 in Northern Liberties. Police said a 17-year-old was outside a friend's house on the 900 block of North Fourth Street, waiting for someone to pick him up, when three unknown men attacked him.

On the video released by police, the victim can be seen walking down the street when he is approached by three men. One of the men punches the teenager, knocking him back. The three then pound on the victim several more times and he is knocked to the ground, where one of the men stomps on him. The three bend over the victim, who is still prone, before running off.

Police said reports did not indicate anything was taken from the teenager, and a motive was not specified.

The victim was unable to provide any detailed information about his attackers because he had been knocked unconscious, police said.

He also suffered broken teeth and was treated at Thomas Jefferson University Hospital, police said.

Anyone with information on the incident is being asked to call East Detectives at 215-686-3243.