CHICAGO (CBS) — A fifth teenager has been charged with attacking people at a Red Line subway stop last month, an assault that was caught on video.

Police said the 16-year-old was arrested Monday afternoon near 62nd and Stony Island, after an anonymous tip identifying him as one of the suspects seen in a community alert about the attack at the Chicago Avenue station on the Red Line on Dec. 29.

The 16-year-old has been charged with two felony counts of aggravated battery, and one felony count of mob action. He was due to appear in Juvenile Court on Tuesday.

Police said he was part of a group of teenagers who attacked three people waiting on the Chicago Avenue platform around 8 p.m. on Dec. 29. The victims – a 26-year-old man, a 28-year-old man, and a 29-year-old woman – told police the teens started kicking and punching them for no reason.

All three victims suffered bruises and abrasions, and the 28-year-old man suffered a fractured eye socket.

A video posted on social media shows several teens repeatedly punching a man in the face, knocking him to the ground.

Police said, so far, five people have been charged in the attack. They believe eight to ten people were responsible for the attack.