Canada on Tuesday banned travellers from Egypt, Nigeria and Malawi over fears of the spread of the new Omicron coronavirus variant, bringing to 10 the number of African countries targeted by Ottawa.

“Foreign nationals who have transited or stayed in these 10 countries cannot enter Canada if they have been in those countries in the last two weeks,” Health Minister Jean-Yves Duclos told a press conference.

The measure takes effect on Wednesday, the government said.

Any Canadians or permanent residents who have been in any of the 10 countries will need to quarantine on arrival and take a Covid test.

Duclos also said “in the coming days,” all air travelers arriving from outside Canada, apart from the United States, will now need to be tested for Covid-19 at their point of entry, and isolate until their test results are available.

First reported to the World Health Organization less than a week ago after being detected in southern Africa earlier in November, the Omicron variant has appeared in well over a dozen countries, stoking global fears about a coronavirus pandemic that has killed more than five million people and savaged economies worldwide.

“The pandemic is not over,” Transport Minister Omar Alghabra added. “Travel measures could change at any moment.”

Canada on Friday banned entry to all travelers from seven southern African countries: Botswana, Swaziland, Lesotho, Mozambique, Namibia, South Africa, and Zimbabwe.

And on Sunday, Canada confirmed it had detected its first cases of the new Omicron strain, in two people who had traveled recently to Nigeria.

The WHO warned on Tuesday that travel bans will not prevent the spread of the new variant, after some 50 countries put similar measures in place.

Canada has reported a total of 1,791,902 coronavirus cases and 29,681 deaths.