CTA surveillance images of Monday’s attack were released by investigators on Wednesday. | Chicago Police

An 81-year-old man is in intensive care after being thrown down the stairs of a Loop “L” station during a robbery on Monday evening. Police are asking for help in identifying his attacker.

The robber grabbed the man’s hand and phone as the victim stepped off of a Brown Line train at the Wabash station around 9:25 p.m., police said.

A struggle ensued and the victim fell down the station staircase. He suffered bleeding on the brain, a cut to his head, swelling and bruising.

Police said the attacker, seen above, is a black man between 19- and 24-years-old. A CWB Chicago source who works closely with Lakeview social service agencies reported that they recognized the attacker as a female who has frequented the area.

Anyone with information about the attacker is asked to call Area Central detectives at 312.747.6384

Monday’s attack is only the latest in which elderly passengers have been targeted on the CTA train system. Earlier this week, police issued a separate request for information about a violent robbery on the Red Line that left a 70-year-old man unable to communicate for two months. More details of that incident are available HERE.