CHICAGO (CBS) — Police were warning people who use the Pedway about three recent robberies in the tunnels connecting the Red Line and Blue Line in the Loop.

According to a community alert, a group of five young men who frequent the CTA tunnels connecting the Red and Blue lines repeatedly have surrounded pedestrians, showed a handgun, beaten the victims, and stolen their property.

Police said the suspects struck at least three times in the tunnels at Monroe and Jackson since the end of January – around 9:15 a.m. on Jan. 30, around 7 a.m. on Feb. 13, and around 7 p.m. on Feb. 14.

Authorities have released surveillance images of four of the suspects.

Surveillance images of four men who have been robbing people in the Pedway tunnels connecting the Red Line and Blue Line in the Loop. (Credit: Chicago Police)

One man was wearing a red hoodie, blue jeans, and red shoes. Another one was dressed in a in camouflage pants and a dark blue jacket with a camouflage hood. A third was wearing a puffy blue ski coat, blue jeans, and tan boots. The fourth was wearing a black coat, black snow hat, faded blue jeans, and black shoes.

Anyone who recognizes the robbers should call Area Central Detectives at 312-747-8384.