OTTAWA, Dec 18 — Canadian Prime Minister Justin Trudeau yesterday said a spike in cases of the Omicron Covid-19 variant was "scary,” while the country’s top medical official made clear the healthcare system could soon be swamped.

Covid-19 case numbers are rapidly increasing in Canada, with several of the 10 provinces reporting big jumps as Omicron replaces Delta as the dominant variant.

"I know the record numbers we’re seeing in parts of the country are scary — but I also know we can get through this,” Trudeau tweeted, urging Canadians to get vaccinated and keep their distance from other people.

Health Minister Jean-Yves Duclos earlier urged provinces to impose more public health measures, and said Canada would once again require people returning home after foreign trips of less than 72 hours to produce a negative test. Tour operators say the measure is onerous and deters travel.

"We’re not in a popularity contest here,” Duclos said, describing the situation as "dramatic and critical.”

Chief medical officer Theresa Tam said that if Omicron did become the dominant variant, "the sheer number of cases could inundate the health system in a very short period of time”.

Duclos also said Canada would lift a ban on travellers from 10 African countries that was imposed last month and reiterated government advice that residents avoid international travel.

Critics said the ban on people who had recently been to South Africa, Nigeria, Egypt and seven other nations made no sense given the rapid spread of Omicron.

"While we recognise the controversial nature of such a prohibition, we believe it was a necessary measure to slow the arrival of Omicron in Canada and buy us some time,” Duclos said.

Britain made a similar announcement on Tuesday, citing community transmission of Omicron.

The provinces of Ontario and Quebec, which together make up around 60 per cent of Canada’s population, this week both reimposed restrictions on public gatherings.

In its second installment of curbs announced this week, Ontario said yesterday that the capacity limit on indoor public places such as restaurants, gyms, and shopping malls would be capped at 50 per cent from Sunday.

The province also put a limit of 10 people for informal social gatherings indoors and 25 people outdoors.

"I know this is not the situation any of us wanted to be in, especially during the holiday season, but it’s clear Omicron will not take a holiday,” said Ontario’s chief medical officer Kieran Moore. — Reuters