Mail was reported stolen from a post office in the village of Veteran, about 200 kilometres west of Red Deer on Friday, and the suspects were later involved in a collision.
Consort RCMP said its officers responded to the theft at about 5:37 a.m., and officers from several detachments attempted to contain the SUV suspected of being involved.
The vehicle was located at about 8:30 a.m., heavily damaged, and was believed to have been driven off an embankment north of Chipman, northeast of Edmonton.
Two adult males in the vehicle suffered serious life-threatening injuries. One was taken by STARS air ambulance, and the other by ground ambulance, to an Edmonton hospital.
The Alberta Serious Incident Response Team is investigating the circumstances surrounding the collision and the actions of police.