DUQUESNE (AP) — Police in western Pennsylvania say a patrol car pursuing a speeding vehicle struck a bus, injuring three people.

Duquesne police say an officer at the entrance to Duquesne Plaza clocked a southbound vehicle traveling 70 mph in a 35 mph zone shortly before 12:30 p.m. Saturday.

The officer pursued with lights and sirens, and the speeding vehicle went through a red light. A bus with a green light went into the intersection, and the officer tried to stop and served, but the patrol car hit the rear driver’s side of the bus.

Police say three people on the bus reported minor injuries and were evaluated at a hospital. An outside police agency will investigate, and police said “disciplinary action against the officer may occur” pending the outcome of the investigation.