Ottawa officials are urging residents to stay home Monday morning as the region recovers from a pair of devastating tornados.

With 400 traffic lights still out, people can expect delays on the road during the morning rush hour, said Anthony Di Monte, the city's general manager of emergency and protective services.

"If they can, please stay home. Those of you who must absolutely circulate on the roads, understand that patience and courtesy will be the top priority," he said.

The plea was seconded by Ottawa police chief Charles Bordeleau.

"Please avoid unnecessary travel. If you can work from home or avoid travelling tomorrow we encourage you to do so," he told reporters Sunday evening.

Environment Canada said two tornadoes hit the region on Friday. The one that hit Dunrobin, a rural Ottawa community about 36 kilometres west of the city's downtown, was likely an EF-3, meaning it had wind speeds of up to 265 km/h.

A second tornado was classified as an EF-2, with wind speeds of up 220 km/h, and affected the area near Hunt Club and Greenbank roads in Ottawa.

After the tornado touched down in Dunrobin, it went east across the Ottawa River, causing serious damage to Gatineau's Mont-Bleu neighbourhood.

Bryce Conrad, President and CEO of Hydro Ottawa, speaks as Mayor Jim Watson, left, Anthony DiMonte, Ottawa's General Manager of Emergency and Protective Services, second from right, and Ottawa Police Chief Charles Bordeleau listen, during a press conference at Larkin House Community Centre, where residents who had lost power or had damaged homes gathered to receive support or hot meals, in Ottawa on Sunday, Sept. 23, 2018. (Justin Tang/The Canadian Press)

Bordeleau urged non-residents to stay away from the affected neighbourhoods to allow emergency vehicles to get in and out.

He also pressed residents to only call 911 for emergencies.

"Non-emergency calls about gas and power service should be directed to the appropriate utilities and not 911," he said.

Bryce Conrad, president and CEO of Hydro Ottawa, said as of 4:45 p.m. on Sunday they were still dealing with 70,000 customers without power, down from over 170,000 when the tornadoes hit Friday. Around 8,100 ​Hydro-Québec customers in the Outaouais are still in the dark and a few thousand Hydro One customers in the Ottawa region are also still without power. Many of these households could be in the dark for days.

With parts of the city still reeling from the storm, English-language schools in Ottawa will be closed Monday.

Both the Ottawa Catholic School Board (OCSB) and the Ottawa-Carleton District School Board (OCDSB) are shutting the schools down.