Police issued an alert after two recent robberies in the North Side Lakeview neighborhood.
In each incident, two men approach a victim from behind, use force and rob them, police said.
Both robberies occurred early Wednesday.
The first robbery happened at about 4 a.m. in the 900 block of West George, police said. The second incident occurred 10 minutes later in the 900 block of West Cornelia.
The suspects were described as two men, between 20 to 30 years of age, who were wearing dark leather jackets and jeans, police said. One of the men was said to be about 5-foot-9 and 170-pounds.
Further details were not available.