British Airways and Virgin have cancelled flights to Tokyo.
BA has cancelled its daily Heathrow service to Tokyo's Narita airport and Saturday's services to the UK from both Narita and Haneda. Virgin Atlantic, which operates daily services to Narita from Heathrow, has cancelled today's flight to Japan and Saturday's service from the airport.
The Foreign Office says it is updating its travel advice for Britons in Japan and the Pacific region.
Friends and relatives of those in Japan can contact the Foreign Office in the UK on 020 7008 1500