Travellers from China, Hong Kong, Japan, Singapore, South Korea and Thailand will need to submit Covid-19 negative test results from within 72 hours of undertaking the journey to India, the Union health ministry said on Thursday.

The mandatory requirement will come into effect from 10am on January 1.

Union health secretary Rajesh Bhushan asked the civil aviation ministry to make operational the “Air Suvidha” portal for travellers from these countries to upload their Covid19 negative RT-PCR test reports and self-declaration forms.

The health ministry said the random tests on two per cent of international passengers from all incoming flights — introduced from December 24 amid the rising counts of daily new Covid-19 cases in many countries — will also continue.

The ministry has described both precautionary moves as intended to “minimise the risk of importation” of any new coronavirus variants from countries with growing epidemics at a time India’s daily new Covid19 cases counts have remained below 300 over the past month.

Experts view China’s Covid-19 data as unreliable -- a database tracking Covid-19 worldwide documented zero new cases as reported by China since December 22. Some fear that the explosive spread of the coronavirus in China has created conditions that could favour the emergence of fresh variants.

“With the (expected) spread in China over the coming weeks, the virus has enormous new avenues to mutate,” said Vinod Scaria, a scientist tracking changes in the coronavirus genome at the Institute of Genomics and Integrative Biology, New Delhi.

“In the absence of data coming out of China, what we need to watch out for are new variants or a new clinical picture of the infection – such as greater virulence,” Scaria said. “The way to do this is through airport surveillance, a close clinical watch on those who turn positive, and increased sequencing.”

Japan’s seven-day average of daily new cases rose to168,000 on December 28 from111,000 on December 1, while South Korea’s daily average rose from 52,000 to 66,000 over the same period. In Hong Kong, the daily new cases have increased from 8,500 to 10,000over the past four weeks.

Thailand’s daily new cases have decreased -- 414 on December 28 from 702 on December 1.

India on Thursday recorded 268 new cases. Its count of active Covid-19 patients roses lightly to 3,552 from 3,468 on Wednesday. Scientists say India’s three Covid-19 waves and its high vaccination coverage are protecting its population from existing variants and only a dramatically different variant could trigger a fresh surge in the country.

Almost all the sequenced coronavirus variants currently in circulation in the country are subline ages or siblings of omicron, which had fuelled the country’s third Covid-19wave in January this year.