TORONTO -- More than 20,000 customers in southwest Ontario were without power Thursday as freezing rain began coating wires and tree branches with ice.

Ontario Hydro was working to restore power, which were scattered throughout the region.

PowerStream, which services communities north of Toronto, has restored power to some 28,000 residents and businesses in the Vaughan, Woodbridge and Kleinburg areas.

But PowerStream says it is still dealing with outages in Barrie, Alliston and Beeton affecting more than 14-thousand customers.

The icy weather also meant a day off for thousands of students across southern Ontario.

Classes and buses were cancelled at the Dufferin-Peel Catholic District School Board, the Peel District School Board and at Halton Catholic schools. Both the Toronto District School Board and the Oxford County board have cancelled buses, but schools remain open.