British Health Secretary Matt Hancock informed that a new, potentially more infectious variant of the coronavirus that causes COVID-19 has been discovered in Britain in cases linked to South Africa.

South Africa's health department recently said that a new genetic mutation of the virus had been found and might be responsible for a recent increase in cases there. While the first mutant was claimed by many to be about 70 per cent more infectious than SARS-CoV-2, Health Secretary informed that the new strain discovered is even more transmissible than the first one.

To curb the spread of COVID-19, Sussex, Oxfordshire, Suffolk, Norfolk, Cambridgeshire, parts of Essex that are not currently in Tier Four, Waverley in Surrey and Hampshire will all enter Tier Four from Boxing Day, Hancock said at a virtual press conference from the Downing Street on Wednesday, Xinhua news agency reported.

Bristol, Gloucestershire, Somerset, Swindon, the Isle of Wight, the New Forest and Northamptonshire, as well as Cheshire and Warrington, will enter Tier Three.

Under the new tougher measures, residents in Tier Four areas must stay at home, with limited exemptions. People are also urged to work from home when they can. Hancock also said that another new variant of the novel coronavirus has been detected in Britain, and two cases have been reported so far.

This new variant is "yet more transmissible" and the development is "highly concerning," he said. Both people had travelled to South Africa, where the variant has been linked to a surge in cases, the BBC reported. Cases and close contacts of cases found in Britain are being quarantined, and the British government is placing "immediate restrictions" on travel from South Africa, according to Hancock.

Anyone who has been in South Africa in the last fortnight and anyone who has been a close contact with someone who has been in South Africa in the past two weeks must quarantine immediately, he said.

(With inputs from IANS)