One person is dead and two others have been seriously injured after a minivan drove the wrong way along Highway 401 and slammed head-on into an oncoming vehicle.

The elderly man driving the van was travelling east in the westbound lanes, west of Highway 427, when he crashed into a westbound minivan at about 7 a.m. on Saturday, Ontario Provincial Police said.

The wrong-way driver, in his 70s, died in the collision. Police have not yet released his identity.

Two passengers in the second vehicle were taken to hospital with serious injuries.

Police aren't sure how the deceased ended up travelling the wrong way on the busy highway.

The area was closed for almost three hours.

Witnesses to the accident are being asked to call the OPP at 1-888-310-1122.