Boris Johnson called senior ministers to an unscheduled meeting on Friday evening to discuss how to contain a new, more virulent variant of the coronavirus. An emergency toughening of Covid-19 restrictions could be announced as soon as Saturday, possibly including restrictions on travel between the south-east of England, including London, and the rest of the country, <em>The Daily Telegraph</em> reported. A spokesman for the prime minister said he was unable to comment on the report immediately. Britain's government on Monday said a rise in new infections might be partly linked to the new variant as the capital and other areas have moved into the highest tier of Covid-19 restrictions. Meanwhile, a severe variant of the coronavirus has been detected in South Africa, which could explain the rapid spread of a second wave that is affecting younger people, South African Minister of Health Zwelini Mkhize said Friday. Known as the 501.V2 Variant, it was identified by South African researchers and details have been sent to the World Health Organisation, Dr Mkhize said in a statement. A team led by the KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP) has sequenced hundreds of virus samples since the pandemic began and "noticed that a particular variant has increasingly dominated the findings of the samples collected in the past two months," he added. South African doctors have remarked that more patients are younger and do not always have other conditions that amplify the virus's effect, but they nonetheless suffer from more severe forms of Covid-19. That "strongly suggests that the current second wave we are experiencing is being driven by this new variant," Dr Mkhize concluded. The research team, led by Tulio de Oliveira, has shared its findings with the scientific community and alerted authorities in Britain, who have "studied their own samples and found that a similar mutation ... was the variant that was driving their resurgence in London," he said.