Two carjackings were reported in March on the North and Near North Sides.
In each incident, someone was approached by four males who got out of a vehicle, flashed a gun and demanded their property and vehicle, Chicago police said in a community alert.
The vehicle used in the first robbery, about 9:10 p.m. March 24 in the 1100 block of North Howe Street, was used to commit the second robbery, about 2:45 a.m. a day later, in the 800 block of West Armitage Avenue, police said.
Police believe the males involved ages range from 17 to 30-years-old, police said.
Anyone with information is asked to contact Area Three detectives at 312-744-8263.