British travellers to Turkey have been warned to be cautious following the terrorist attack on an Istanbul nightclub which killed 39 people.
The Foreign and Commonwealth Office altered its travel advice to the country in the wake of the atrocity in the early hours of Sunday.
Around 600 revellers were in the Reina nightclub celebrating the new year when a gunman attacked. The attacker has not yet been found although Islamic State claimed responsibility for the outrage.
Istanbul was already on high alert with some 17,000 police officers on duty in the city following a string of terror attacks, including a gun and bomb attack on Ataturk airport in June which killed 41 people and the deaths of 44 in a bombing outside a football stadium last month.
The FCO said: “On 1 January, there was an attack on the Reina nightclub in Ortakoy, Istanbul, causing a large number of casualties.
“There is an ongoing police operation in Istanbul as a result of the attack, and the attacker may still be at large. You should exercise vigilance and caution at this time, and follow the advice and instructions of the security authorities.”