It happened just before 9 p.m. Thursday in the 8300-block of South Indiana Avenue.
Police say they pulled over a vehicle with three people after receiving a report that weapons were inside. The driver decided to take off instead of cooperating and hit another unmarked police car and then hit another vehicle. The officer inside the unmarked police car was injured.
Most people hurt in the accident have been treated and released, but the two suspects were still being treated at Northwestern Memorial Hospital Friday morning. Another suspect is in custody at the District 6 Police Station.
Police say they did end up finding weapons inside the vehicle in question.