In the major Indian cities, the Omicron variant of the coronavirus is accounting for more than 50 per cent of the fresh cases of the infection and the massive surge in the number of cases over the last one week is indicative of a third wave of the pandemic, as is being witnessed in several countries, Dr N K Arora, the chairman of the COVID-19 working group of the NTAGI, said on Tuesday.

Omicron is being detected in most of the states in the country, he told PTI.