A man has been upgraded to stable condition in hospital after a head-on collision with a school bus.

It happened on Highway 4 north of Exeter between Hurondale Road and MacDonald Road around 3:30 p.m. Monday.

OPP say a Honda Accord was travelling southbound when it crossed the centre line and collided with the school bus.

The 51-year-old London man had to be extricated from his sedan and airlifted to a London hospital.

None of the 15 students on the bus or the driver were injured.