UK, South African and Brazilian variants of the coronavirus have infected 795 people in India so far, the Health Ministry said Tuesday afternoon.
The spike in infections by mutant strains - up from 400 on March 18, an increase of nearly 50 per cent in five days - comes amid a surge in fresh Covid cases across India over the past few weeks.
Furthermore, of the 395 new mutant virus cases reported since March 18, at least 326 are from Punjab and have been identified as the strain that originated in the United Kingdom late last year.
This morning Punjab Chief Minister Amarinder Singh flagged the spread of the UK variant in his state - genome sequencing of 81 per cent of around 400 samples identified the B117 strain.
The Chief Minister urged Prime Minister Narendra Modi and the centre to allow younger people to be included in the vaccination drive, in an effort to break the chain of transmission.
Scientists believe the UK, South African and Brazilian strains are more contagious, and that each also have the potential to re-infect those who had been previously infected with SARS-CoV-2 virus.
Last week, however, the government said there are, as yet, no cases of re-infection in India by mutant strains of the virus. The UK variant of the virus already accounts for 98 per cent of all cases in that country, and 90 per cent of all cases in Spain. India reported its first case on December 29.
India has reported an alarming spike in coronavirus cases in recent weeks, with over 40,000 new cases reported every day since March 20. The active caseload - the number of new cases minus recoveries - increased for a 13th straight day today and stands at over 3.45 lakh.
The nationwide vaccination drive began January 16 and, this morning, the centre said it would enter the third phase on April 1, in which all those over 45 can get the vaccine. The current phase sees those over 60 and those over 45 but with co-morbidities eligible to get the shot.
Last month AIIMS chief Dr Randeep Guleria told NDTV that the vaccines currently deployed - Covishield and Covaxin - should work against the new strains as well. In January Bharat Biotech, the makers of Covaxin, said its drug had been found effective against the UK strain.
Concern over an alarming increase in cases in India - 131,512 in the past 72 hours - has been underlined by a spike in the 'R', or 'reproduction rate', which jumped to 1.33 today from 1.13 last week.