New cases of the Omicron coronavirus variant have been detected around the world, with two cases reported in Australia, and more countries try to seal themselves off by imposing travel restrictions.

First discovered in South Africa, Omicron has since been recorded in Belgium, Botswana, Germany, Hong Kong, Israel, Italy, and the United Kingdom.

Austria was investigating a suspected case today and in France, Health Minister Olivier Veran said Omicron was probably already there.

The discovery of Omicron, dubbed a “variant of concern” on Friday by the World Health Organization, sparked worries that it could resist vaccines and prolong the nearly two-year COVID pandemic.

Countries have imposed a wave of travel bans or curbs on Southern Africa. Israel announced late on Saturday it would ban the entry of all foreigners and reintroduce counterterrorism phone-tracking technology to contain the spread of the variant.

Britain’s government has defended the pace and scale of its response to the new Omicron strain of COVID-19. From Tuesday, all passengers arriving in Britain are being instructed to take a PCR test for COVID-19, and self-isolate until they register negative.

Meanwhile,in Netherlands health authorities say they have detected 61 COVID-19 cases among people who flew in from South Africa and say they believe some of the infections are of the new omicron variant.

In a statement , the Dutch Health Authority said that the cases were discovered among 624 passengers who arrived at Amsterdam’s Schiphol Airport on two flights on Friday.

Restrictions to public life to curb coronavirus infections have sparked opposition in Switzerland.

Bahrain, Saudi Arabia, and Sudan have suspended flights with a number of African countries due to Omicron.

Saudi's Interior Ministry, said direct flights with Angola, Comoros, Madagascar, Malawi, Mauritius, Seychelles, and Zambia had been suspended.

On Friday, the kingdom banned flights from Botswana, Eswatini, Lesotho, Mozambique, Namibia, South Africa, and Zimbabwe amid Omicron fears.

Health authorities in Sudan also banned flights from Botswana, Lesotho, Namibia, South Africa, and Zimbabwe over variant.

Omicron is potentially more contagious than previous variants, but experts do not know yet if it will cause more or less severe COVID-19.