The health secretary has announced two cases have been detected of another new strain of the coronavirus in the UK.
Both were contacts of cases who have travelled from South Africa over the past few weeks, he said.
He said: “This new variant is highly concerning because it is yet more transmissible and it appears to have mutated further than the new variant that has been discovered in the UK.”
The health secretary said both cases and close contacts of the cases have been quarantined.
There are immediate restrictions on travel from South Africa and the government is telling those who have been in contact with anyone who has been in South Africa in the last fortnight that they must quarantine.
He added: “These measures are temporary while we investigate further this new strain which is shortly to be analysed at Porton Down.”