The Foreign Office is urging travellers to avoid all non-essential travel to major Turkish cities following November’s bomb attacks in Istanbul which killed at least 27 people, including three British citizens, and injured 450.

Updated advice on the Foreign and Commonwealth website (www.fco.gov.uk) now reads: 'There is a high threat from terrorism in Turkey. We urge you to be vigilant in all parts of the country, and especially in the vicinity of potential terrorist targets.

'We advise against all but the most essential travel to Istanbul and other major cities, until the situation becomes clearer.'

The Turkish prime minister Recep Tayyip Erdogan, speaking on David Frost’s BBC programme, responded to FCO advice by insisting his country is safe for anyone to visit.