Noting that the Omicron variant of the coronavirus accounts for more than 50 per cent of cases in major Indian cities, Dr N K Arora, chairperson of the Covid working group NTAGI, says the massive surge in numbers indicates a third wave, but there is no need to panic.

Citing the example of South Africa, where the number of Omicron cases went up rapidly, he pointed out that in two weeks, the figure started coming down again and most of the cases were either asymptomatic or had a mild illness.

"Along with the decoupling of the total number of Covid cases vis-a-vis those requiring hospitalisation -- these factors indicate that the Omicron wave in South Africa may soon subside," the chairman of the National Technical Advisory Group on Immunisation (NTAGI) told PTI.

Noting that in major Indian cities, Omicron is accounting for over 50 per cent of the fresh cases, he said, "The galloping increase in the number of Covid cases over the last one week is indicative of the third wave, as is being seen in several other countries across the globe."

Arora said over 80 per cent of the people in the country have been infected with the virus naturally, more than 90 per cent of the adults have received at least one dose of an anti-Covid vaccine and over 65 per cent are fully vaccinated.

There are some epidemiological similarities between South Africa and India, Arora pointed out. The natural infection rates in both the countries are very high, he said, adding that however, the immunisation rates in India are several fold higher.

"In view of this, we may see a somewhat similar pattern in India as far as the third wave is concerned."

"Looking at the behaviour of the Covid infection in the last seven to 10 days in India, I feel that we may be in for a third wave peak very soon," he said.

Arora, however, asserted that there is no need to press the panic button.

"Those who are yet to take the vaccine or are partially immunised should get the jab for protection against severe disease and hospitalisation. Also, one should strictly follow Covid-appropriate behaviour," he said.

A total of 1,892 Omicron cases have so far been detected across 23 states and Union territories in the country and of the patients, 766 have either recuperated or migrated, the Union health ministry said on Tuesday.

Maharashtra has recorded the highest number of 568 Omicron cases, followed by Delhi (382), Kerala (185), Rajasthan (174), Gujarat (152) and Tamil Nadu (121).

With 37,379 fresh cases, India's Covid-19 tally has climbed to 3,49,60,261, while the number of active cases of the infection has gone up to 1,71,830, according to the ministry's data updated at 8 am.