India's Omicron tally crossed 350 on Friday, with the health ministry on Christmas Eve recording over 120 fresh cases of the new Covid strain in 24 hours.

Indian Health Ministry said that as many as 122 new Omicron cases were reported in the past 24 hours, indicating the caseload nearly tripled in just one day. Delhi and the western state of Maharashtra are the worst hit, according to the Ministry data.

Asunder Maharashtra and Delhi, the southern Indian states of Telangana, Tamil Nadu and Karnataka also reported over 30 Omicron cases, as per the latest figures.

"The World Health Organisation on December 7 said that Omicron has a significant growth advantage over Delta which means, it has greater transmissibility.

Read: Omicron less likely to put you in the hospital, studies say

"Omicron cases double within 1.5-3 days, so we have to remain vigilant with Covid appropriate behaviour,” Health Secretary Rajesh Bhushan said at a media briefing in the national capital in the evening.

Overall, India recorded 6,650 new Covid-19 cases and 374 deaths in 24 hours till Friday morning.

Alarmed by the rising Omicron cases, India's federal government on Wednesday warned states that "the variant is three times more transmissible than the Delta" and directed them to take appropriate action to rein in its spread, including activation of a "war room".

Soon after the directive was issued, state after state announced curbs to prevent any mass outbreak of the Omicron strain.

While Delhi banned all Christmas and New Year gatherings, the neighbouring state of Haryana made it clear that unvaccinated people won't be allowed to enter public places like malls, restaurants, banks and offices from January 1.

Read: U.S. announces first recorded Omicron-related death

Another northern Indian state, Punjab, told all government employees that they won't get their salary unless they upload their vaccination certificate on the official portal.

On the other hand, the southern state of Karnataka made it mandatory for all international travellers to undergo quarantine for a week post-arrival, followed by an RT-PCR test on the eight day.

The World Health Organization has already warned that the "variant of concern" -- first detected in South Africa -- could have severe consequences in several countries.