NEW DELHI - India is reimposing Covid-19 restrictions, including a seven-day home quarantine, on 12 economies including Singapore from Wednesday (Dec 1).

The move comes amid concerns over the emergence of the Omicron variant of the coronavirus that was first detected in South Africa.

The 12 economies are categorised as "at risk" by the Indian authorities. Besides Singapore, this category includes the United Kingdom, South Africa, Brazil, Bangladesh, Israel and Hong Kong.

"Passengers originating or transiting from at-risk countries shall be informed by the airlines that they will undergo post-arrival testing, quarantine if tested negative, stringent isolation protocols if tested positive," said a government statement.

Travellers from at-risk countries will have to pay for the Covid-19 test at the airport and wait for the result.

Those who test negative will have to undergo home quarantine for seven days and then self-monitor for another seven days, in addition to a test on the eighth day of arrival.

Samples of positive cases will be sent for genome sequencing to identify the variant.

The restrictions from Wednesday come shortly after the vaccinated travel lane (VTL) between India and Singapore took effect on Monday evening, with flights landing in both countries.

Under the VTL scheme, fully vaccinated travellers from VTL countries may enter Singapore without quarantine and just need to undergo Covid-19 testing.

Singapore has not detected any cases of the Omicron variant to date.

India's Ministry of Health and Family Welfare announced the new restrictions on Sunday evening following a meeting chaired by Prime Minister Narendra Modi to review the emerging situation, said the government statement.

The new guidelines come at a time when India is moving towards opening up international travel. But the government is now reviewing the decision to restart international flights from Dec 15.