Ontario’s police watchdog has invoked its mandate following a collision involving an OPP cruiser in the Municipality of North Middlesex that left two people seriously injured. Emergency crews were called to the intersection of Nairn Road and Centre Road at about 3:30 p.m. Sunday after a crash involving an OPP cruiser and a passenger vehicle, police said. Members of the Middlesex County OPP, Middlesex-London Paramedic Service and North Middlesex Fire Services responded to the scene. The driver of the passenger vehicle and an OPP officer were both taken to hospital with serious injuries. The Special Investigations Unit, which investigates incidents involving police that result in serious injury, death or allegations of sexual assault, is investigating the circumstances surrounding the collision. The intersection remained closed Sunday afternoon and was expected to stay closed for several hours while investigators and emergency personnel worked at the scene. No further details were immediately available. With files from CTV News London’s Koylan Azofeifa