The suspects drove up to a 7-Eleven store in the 800-block of Higgins Road in a lighter color BMW 7 series with no rear registration at about 3:34 a.m. police said.
The suspects had their faces covered as they removed money from the register. One of the suspects was armed with a handgun and struck the clerk in the face, police said. The clerk was not seriously injured and was treated at the scene.
After exiting the store, the suspects got in the BMW and drove south on Cumberland Avenue over I-90.
Anyone with information is asked to contact the Park Ridge Police Department at 847-318-5252.