Surveillance video showing the latest teen attack at a SEPTA subway station is expected to be released Tuesday.

Monday afternoon's attack began on the train near the 15th Street platform of SEPTA's Market-Frankford Line and left a man in his 50s hospitalized.

A group of six to 12 teenagers approached the man on the train around 3 p.m. and one of the boys struck him repeatedly in the head following an argument, police said.

The altercation spilled out onto the platform on 15th St.

Doctors treated the victim for concussion-like symptoms and had to reset his jaw.

Police have not yet released a description of the teens. SEPTA officials said they will likely release surveillance video of the attack on Tuesday.

This attack came about two weeks after a group of teens beat up another teen on the Walnut-Locust Station platform along SEPTA's Broad Street Line. Investigators didn't say if the two attacks were connected.