Two explosions outside a football stadium in Istanbul on Saturday have killed 38 injured 155.
One blast was caused by a car bomb which targeted a riot police bus directly outside the stadium while the other was a suspected suicide bomber, according to reports.
The Foreign and Commonwealth Office told British travellers to avoid the Macka/Dolmabahce area of Istanbul following the attack.
"You should avoid the area, remain vigilant and follow the advice of the local security authorities," it said.
A Kurdish militant group has claimed responsibility, saying the Turkish people were not the target.
The World Travel & Tourism Council (WTTC) condemned the attacks, which come as Turkey was beginning to recover from the attempted coup in July and the attack by three suicide bombers at Istanbul’s Ataturk airport in June.
President and CEO David Scowsill said: "We are extremely saddened to hear of the attacks in Istanbul. Our heart goes out to the friends and family of the victims.
"Now more than ever it is important that public and private sectors work together to respond to the threats of terrorism. Turkey is a beautiful tourism destination and we stand by the country in these difficult times. We look forward to the time when the security situation stabilises and the tourism numbers start to build again."
