Authorities are searching for the identities of a group of hooligans filmed in a violent attack on at least two men.
Video released on Sunday shows snipets of the violence that took place in a Philadelphia subway station last week, when roughly a half-dozen young men mobbed at least two other men, punching them and stomping them in the head while lying prone on the ground.
The brutal scene took place at the Race-Vine station on Thursday around 3.45pm, beginning as a snowball fight on the street before moving into the station, according to transit authorities cited by the Philadelphia Inquirer.
The 38-second video clip begins with a man in a red sweatshirt lying on the ground, apparently trying to cover his head with his hands.
At least three attackers kick and stomp the man in the head before one begins whaling away with punches as he stands over the helpless man.
As the man in the red sweatshirt is assaulted, a bystander in a blue jacket is seen appearing to plead with the assailants, gesturing with open palms toward the man on the ground.
Seconds later, three assailants swarm the man in the blue jacket, throwing punches which he attempts to fend off.
After a cut in the video, the man in the blue jacket is seen lying prone on the ground under assault by at least three attackers.
The assailants punch the man and kick him in the head area before one bends down and appears to rifle through the man's pockets.
They finally desist and flee when a female intervenes and pleads on behalf of the man in the blue jacket.
Transit cops are referring to the individuals sought as 'combatants,' rather than suspects, saying they want to conduct interviews before making a determination on criminal charges.
Police say three people sustained minor injuries in the violence.
'It's ridiculous,' subway rider Justin Harris said of the incident to ABC 6. 'It's been going on though, it's not new. It's not new at all.'