CHICAGO (CBS) — Police on Saturday issued a warning about a string of robberies that have been happening at the 79th Street Red Line station.

In each incident, the robbers came up to the victim on the platform, took out a gun, hit the victim, and demanded money, police said.

The robberies all happened at the Red Line station, located in the middle of the Dan Ryan Expressway between the Greater Grand Crossing and Chatham communities.

They happened at 11 p.m. Friday, Jan. 3; 9:10 p.m. Wednesday, Jan. 8; and 1:30 a.m. Friday, Jan. 10.

One suspect is described as a black male between 22 and 29 years old, standing 5 feet 5 to 5 feet 9 inches tall and weighing 140 to 160 pounds, with short black hair and several facial tattoos.

This latest report comes on the heels of a string of robberies on the Red Line – mostly targeting stations in the downtown area and Near North Side. At a Chicago Police community meeting in Lakeview on Wednesday, some attendees said they feel police are scarce on Chicago ‘L’ lines.

Police emphasize that you should always be aware of your surroundings, report suspicious activity immediately, make transactions in a public place, remember a suspect’s unique characteristics, and never pursue a fleeing assailant.

Anyone with information on these robberies is asked to call (312) 747-8273.