Two drivers suffered serious injuries in a head-on collision in the Blair section of Cambridge Thursday afternoon.

The crash occurred around 4:45 p.m., on Blair Road near Meadowcreek Lane, south of Fountain Street.

It involved a school bus, which ended up in a ditch along the road, and an SUV. Police would not say which vehicle crossed to the wrong side of the road in the moments before the collision.

The 48-year-old woman driving the SUV was airlifted to a Hamilton hospital for treatment. The driver of the school bus was taken away from the scene by an ambulance.

There were no children aboard the school bus, and no passengers in the SUV.

The collision left the bus with enough damage that it could not be driven away. Waterloo Regional Police said heavy equipment would be brought in to remove it from the area.

Police closed Blair between Fountain and George Street in the aftermath of the collision. It was expected to remain closed until late Thursday night.