TORONTO - Wintry conditions are wreaking havoc on Ontario's highways as parts of the province begin to dig out from the year's first major snowstorm.

Ontario Provincial Police say they have been busy since Wednesday responding to numerous reports of vehicle accidents from Windsor all the way to the Greater Toronto Area.

They say most calls have been for minor fender-benders and one-vehicle collisions, except for one potentially serious incident in London on Wednesday.

West Region Sgt. Dave Rektor says an officer had his parked police cruiser rear-ended on Highway 401 around 5:30 p.m. when he went to assist another motorist who had driven into a ditch.

The officer was not injured because he was out of the car at the time, but the cruiser was extensively damaged.

Flurries began to fall late on Boxing day and residents in the Toronto area woke up Thursday to about 10 centimetres of snow.