Police said the first robbery happened in the 200 block of West Madison Street at 6:30 a.m. followed by a second robbery in the 0-100 block of West Lake Street at 7:10 a.m.
In each incident, a person who implied that they were armed entered a business and announced a robbery, police said.
During one robbery, the suspect ordered a restaurant employee to stay in a bathroom.
Police said the suspect is described as a man between 28 and 35 years old. He wears a black jacket, dark-colored pants, a black ski mask and white gym shoes.
Police asked anyone with information to contact them at 312-744-8263.
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