A man in his 70s is in serious but stable condition after a two-vehicle collision in the Durham region on Thursday afternoon. 

The elderly man was transported by air ambulance to Sunnybrook Hospital with critical injuries, says Ornge, Ontario's air ambulance service.

The collision was between a car and a truck that was pulling a trailer at Westney and Taunton roads near the border of Ajax and Pickering.

Police say those inside of the truck had only minor injuries. Officers were unable to confirm how many passengers were inside.

The elderly man is in stable condition and undergoing tests to determine the extent to his injuries. 

The road has been closed from Harwood Avenue to Ravenscroft Road.