Two armed robberies happened hours apart early Thursday on the same block in the South Shore neighborhood.
A suspect either pulled a firearm or implied he had one during both robberies, according to the community alert from Area South detectives.
The robberies happened in the 7600 block of South Exchange, the first about 1 a.m. and the second at 6 a.m., police said.
The suspects are described as black male teens 15-19 , 5-foot-10 to 6-foot-1.
Anyone with information should call Area South detectives at (312) 747-8273.