CHICAGO (AP) — A Chicago police officer has been hospitalized in critical condition after she was shot on the city’s South Side.

In a news conference at the University of Chicago Medical Center, Police Supt. David Brown said at 5:42 p.m. Wednesday, two uniformed officers were in a marked squad car attempting a traffic stop.

The car the officers were trying to pull over first sped up, and then slowed down to pull even with the squad car.

Brown says that at that point, someone in the car started firing a gun at the officers. He says the officer who was driving was shot and wounded in her upper body. She’s in critical but stable condition. Her name hasn’t been released.