Four people were injured after a serious two-car collision on Montreal Road at Marier Avenue Tuesday morning.

Firefighters had to extricate two passengers from one vehicle after the collision, which happened at about 6:30 a.m. Tuesday.

Paramedics said the 25-year-old male driver who needed to be extricated from his vehicle was in serious but stable condition. His passenger, a 22-year-old woman, was also sent to hospital with possible head injuries. She is also in serious but stable condition.

The two people in the other car, a man and woman in their 50s, were treated for minor injuries.

Police had closed Montreal Road between Olmstead and Begin Streets while they investigated, but have since reopened the intersection.