Much of eastern Canada was snowed-in Wednesday after a blizzard swept through the region, disrupting flights and causing widespread havoc for motorists in Montreal, Toronto and the capital Ottawa.

It was the third major snow storm in as many weeks to hit these parts.

The Great Lakes region was the most affected. Almost half of all early morning flights from the nation's busiest airport in Toronto were cancelled or delayed, according to the airport authority.

Montreal also grounded hundreds of aircraft as a precaution as the storm swept eastward, dropping up to a foot of snow (30 centimeters), according to Environment Canada.

In Ottawa, federal government workers were asked to stay home in order to make road clearing easier, while authorities still reported a spike in the number of collisions during the morning commute in the capital, as well as in Toronto and Montreal.

Further east, universities in Quebec City were shuttered for the day as blowing snow closed highways, while on the Atlantic Coast officials called on everyone to just stay home amid a freezing rain warning.