Chicago police are asking for the public's help with identifying three men they said robbed a passenger at gunpoint on the CTA Blue Line on Monday. 

The incident happened around 7:40 p.m. in the 5000 block of South Kedzie Avenue in the Gage Park neighborhood. 

Police said the victim was on the train when one of the suspects displayed a handgun and took the victim's property while the two others assisted by preventing the train doors from closing, allowing the suspect to escape.

All three men were captured on surveillance cameras wearing dark hoodies and black face masks.

Anyone with information is asked to contact Public Transportation Detectives at 312-745 4447 or submit an anonymous tip at CPDTIP.com and use reference #JK103948