A female pedestrian was airlifted to a trauma centre Thursday morning after a serious collision in Ajax.

The collision happened at Middlecote Drive and Taunton Road at around 11:10 a.m.

Durham Regional Police said that the collision was between a grey Toyota Camry and a green BMW.

After colliding, the Toyota Camry left the road and struck a 31-year-old female pedestrian who was waiting at a bus stop. The vehicle then rolled over into a ditch, coming to rest on its roof.

The pedestrian was transported to a local hospital but was later airlifted to a Toronto-area hospital. She is in serious condition, police say.

The driver of the Toyota Camry was taken to a local hospital with minor injuries.

The driver of the BMW was not injured.

Roads in the area were closed for several hours while police investigated the incident, but they have since reopened.

Durham police are asking anyone who may have witnessed the collision to contact investigators at 905-579-1520 or to reach out to Crime Stoppers anonymously.