Highway 17 has reopened as Ontario's Special Investigations Unit investigates a crash in Petawawa, Ont., at Paquette Road.
OPP first reported the head-on collision at 5:30 p.m. where police say a vehicle they were pursuing crashed with a vehicle heading eastbound.
Witnesses told CBC News they saw a Toyota Rav 4 speeding down the highway being pursued by police vehicles just prior to the collision.
One witness said she was pulled over by construction workers at Highway 17 and Paquette Road and told to stay in her car because a high-speed chase was coming towards them.
Danielle Deswert of Pembroke, Ont., said she was told the OPP had laid down a spike belt on the highway. Minutes later the Rav 4 came speeding down the road.
Deswert said she heard a loud crash and then emergency workers swarmed the area, adding she saw the driver of the SUV taken into custody.
At least one person involved in the collision had to be extricated from their vehicle.
The highway was closed for several hours but reopened during morning rush hour Wednesday.