A suicide bomber suspected to be affiliated with the Islamic State (IS) has killed 10 people and injured more than a dozen more in the Turkish city of Istanbul.

At least nine of the ten people killed and the majority of the 15 people wounded in the blast were German tourists.

The attack occurred near the Blue Mosque in the Sultanahmet district of Istanbul, a part of the old city of Istanbul that is popular with tourists form around the world.

Turkish authorities say they have identified the bomber from body parts as a Syrian man born in 1988, but no group has yet claimed responsibility for the attack.

In a telephone call, Turkish Prime Minister Ahmet Davutoglu is reported to have promised German Chancellor Angela Merkel that Turksih authorities would find and punish those responsible for the bombing.

Following news of the attack, Merkel commented:

“Today Istanbul was hit; Paris has been hit, Tunisia has been hit, Ankara has been hit before. International terrorism is once again showing its cruel and inhuman face today.”

In a statement on its website, Germany’s foreign ministry has urged all tourists in Istanbul to avoid large crowds and tourist attractions, and warned that further attacks across Turkey are expected.

The UK foreign office notes that there is a high threat of terrorism in Turkey and that tourists to be “vigilant”. Tourists are urged to avoid areas of Turkey near to the Syrian border.