The UK has detected two cases of another “more transmissible” variant of coronavirus, the health secretary Matt Hancock says.
Both people had travelled to South Africa, where the variant has been linked to a surge in cases.
Travel restrictions with South Africa have been imposed.
Anyone who has travelled there in the past fortnight, and anyone they have been in contact with, are being told to quarantine immediately.
Mr Hancock said: “We are incredibly grateful to the South African government for the rigour of their science and the openness and the transparency with which they have rightly acted as we did when we discovered a new variant here.”