Police said an officer on patrol near North and West avenues at about 4:45 a.m. interrupted a burglary in a liquor store.
The suspects fled in two vehicles, a white Dodge Challenger and an Alfa Romeo, police said.
The Alfa Romeo struck an Elmhurst police squad car and officers pursued the car on I-290 to Austin Avenue, where the vehicle came to a stop, police said. Two suspects were then taken into custody, police said.
The police officer whose squad car was hit was not injured. The Dodge Challenger was last seen fleeing on I-290.