CHICAGO (CBS)–Chicago police are looking for a group of male teenagers wanted in connection with several attacks that happened Dec. 29 at the Chicago Avenue Red Line station.

A Facebook video shows a man being beaten during one of the attacks:

Police said a ‘large group of teens’ surrounded  and attacked passengers waiting to get on the train around 7:15 p.m. The offenders fled after the attacks and have not been apprehended, according to police.

Police issued a community alert about the incidents on Monday. All the suspected offenders are between 15 and 19-years-old, police said.