Police are warning residents after a pair of robberies were reported over the last couple of weeks on CTA property in Lawndale on the West Side.
In each case, someone approached a person on a CTA platform or train and took property by force, Chicago police said in an alert.
Both took place in the 2000 block of South Kostner Avenue, police said. One happened about 3:30 p.m. July 3 and the other about 1:10 p.m. July 9.
The suspect is described by police as a 13 to 17-year-old boy.
Anyone with information about the robberies is asked to contact Area Central detectives at 312-747-8380.