Canada's largest city Toronto and much of its suburbs will be placed under lockdown beginning Monday due to the spread of Covid-19, Ontario Premier Doug Ford announced.
"I've been clear on this: the situation is extremely serious and further action is required," Ford told journalists on Friday.
"Effective Monday, November 23 at 12:01 am, Toronto and Peel will be moved into lockdown."
The lockdown, whose restrictions include a ban on indoor private gatherings, will last at least 28 days and violators can be fined CAN$750 ($570).
Outside gatherings will be limited to 10 people, as will religious services, funerals and weddings.
Hair salons and other personal care locations as well as gyms and casinos will be closed.
Schools will remain open, but restaurants and non-essential stores will only be open for pickup and delivery.
"We can't risk overwhelming our hospitals," said Ford, with Canada's most populous province having just passed 100,000 coronavirus infections.
Prime Minister Justin Trudeau had earlier warned Canadians of "a long winter ahead" and the risk of overwhelming hospitals as infections spike.
"If you are planning to see friends this weekend, maybe don't," Trudeau said.
"There was a birthday party or a gathering for dinner you were thinking about doing -- don't do it."
Trudeau said Canadians would have to take precautions "as the weather drives us indoors."
"It'll be tough. But we know what we have to do," he said.
The country had a total of 317,000 cases and 11,273 deaths on Friday.
Canada has averaged nearly 4,800 daily cases and 65 deaths over the past seven days, a sharp increase in numbers.
Without concerted steps to stem the virus, Trudeau warned, new daily cases are projected to jump as high as 60,000 by the end of December.