Passengers arriving in Mumbai from South Africa, where a new coronavirus variant has been detected, will be quarantined, ANI reported on Saturday.

The samples of the passengers will be sent for genome sequencing, a test that is crucial for detecting new variants of the coronavirus, Mumbai Mayor Kishori Pednekar said.

The mayor added that there were no restrictions on outbound flights. “But this decision [to quarantine passengers] has been taken keeping in view the past experience,” she told ANI. “There is an increased risk of coronavirus in foreign countries, so those coming from outside will have to undergo genome tests.”

The new strain of Covid-19, which the World Health Organization on Friday classified as a “variant of concern” and named Omicron, was first detected in South Africa on November 24. Cases of the variant have also been found in Botswana, Belgium and Hong Kong.

Scientists have said that the variant has a “very unusual constellation” of mutations, which may help it evade the body’s immune system. They are trying to understand its possible implications.

As scientists study the variant, many countries have imposed travel restrictions on southern African nations.

The United States will not allow flights from South Africa, Botswana, Namibia, Zimbabwe, Lesotho, Eswatini and Malawi, the BBC reported. The United Kingdom will also not allow entry to travellers from these countries, unless they are UK or Irish nationals.

In India, the central government has directed the states to rigorously screen international travellers.

“This variant [detected in South Africa] is reported to have a significantly high number of mutations, and thus, has serious public health implications for the country, in view of recently relaxed visa restrictions and opening up of international travel,” Union Health Secretary Rajesh Bhushan had said in a letter to the states on Thursday.

On Saturday, Prime Minister Narendra Modi held a meeting with officials to discuss the new Covid-19 variant. He asked them to review plans to ease international travel restrictions. Modi emphasised on the need to test all international arrivals, specifically those from “at risk” countries.

Modi said that in view of the emergence of the variant, people need to be more cautious, wear masks and practice physical distancing.