Digital display boards show cancelled flights to London - Heathrow at O.R. Tambo International Airport in Johannesburg, South Africa, November 26, 2021. (REUTERS/ Sumaya Hisham/File Photo)

The discovery of the variant has sparked global concern, a wave of travel bans or curbs and a sell-off on financial markets on Friday as investors worried that Omicron could stall a global recovery from the nearly two-year pandemic.

Israel said it would ban the entry of all foreigners into the country and reintroduce counter-terrorism phone-tracking technology to contain the spread of the variant.  

Two linked cases of Omicron detected in Britain were connected to travel to southern Africa, British health minister Sajid Javid said.

The health ministry in the German state of Bavaria also announced two confirmed cases of the variant. The two people entered Germany at Munich airport on November 24, before Germany designated South Africa as a virus-variant area, and were now isolating, said the ministry, indicating without stating explicitly that the people had travelled from South Africa. 

In Italy, the National Health Institute said a case of the new variant had been detected in Milan in a person coming from Mozambique.

Czech health authorities also said they were examining a suspected case of the variant in a person who spent time in Namibia.

Passengers wait to board flights, amidst the spread of the new SARS-CoV-2 variant, at O.R. Tambo International Airport in Johannesburg, South Africa, November 27, 2021. (REUTERS/ Sumaya Hisham)

Omicron, dubbed a "variant of concern" by the World Health Organization, is potentially more contagious than previous variants of the disease, although experts do not know yet if it will cause more or less severe COVID-19 compared to other strains.

England's Chief Medical Officer, Chris Witty, said that there was still much uncertainty around Omicron, but "there is a reasonable chance that at least there will be some degree of vaccine escape with this variant".

The variant was first discovered in South Africa and had also since been detected in Belgium, Botswana, Israel and Hong Kong.

Dutch authorities said 61 of around 600 people who arrived in Amsterdam on two flights from South Africa on Friday had tested positive for the coronavirus. Health authorities were carrying out further tests to see if those cases involved the new variant.  

The US Centers for Disease Control and Prevention (CDC) and State Department added on Saturday to Washington's previously announced travel restrictions, advising against travel to eight southern African countries.

Also on Saturday, Australia said it would ban non-citizens who have been in nine southern African countries from entering and will require supervised 14-day quarantines for Australian citizens returning from there.  

The restriction takes effect on Monday, the document says. Delegates attending G20 meetings, which Indonesia chairs, will not be affected by the ban.

Japan and Britain said they were extending travel curbs to more African countries, while South Korea, Sri Lanka, Thailand, Oman, Kuwait and Hungary announced new travel restrictions.

South Africa is worried that the curbs will hurt tourism and other sectors of its economy, the foreign ministry said on Saturday, adding the government is engaging with countries that have imposed travel bans to persuade them to reconsider.