ANKARA • Turkish President Recep Tayyip Erdogan said an attack on Istanbul's tourist heart yesterday that killed 10 people and wounded 15 was carried out by a Syrian suicide bomber.
Officials have confirmed that the man is a member of the Islamic State in Iraq and Syria (ISIS).
Turkey has been on high alert after a series of attacks blamed on ISIS, including a twin suicide bombing at a peace rally in Ankara last October that killed 103 people.
"I strongly condemn the terror attack which was carried out by a suicide bomber of Syrian origin," Mr Erdogan said in a speech in Ankara in his first reaction to the blast.
"Unfortunately... there are fatalities, including locals and foreigners. This incident showed again we have to stand together in the face of terror.
"Turkey's determined position will not change. We don't make any difference between the names or abbreviations (of terror groups)."
Most of the 10 people killed in the blast at the popular tourist venue, Sultanahmet Square, were German citizens, Turkish Prime Minister Ahmet Davutoglu told German Chancellor Angela Merkel by phone, sources in Mr Davutoglu's office said.
The dull thud of the blast was heard in districts several kilometres away, residents said.
Tourist sites, including the Hagia Sophia and the nearby Basilica Cistern, were closed on the governor's orders.
In the aftermath of the suicide bombing, Germany cautioned its citizens to avoid crowds and tourist sites in Istanbul, a city of 14 million. It also warned of possible "political tensions as well as violent clashes and terrorist attacks across the country".
Singapore's Ministry of Foreign Affairs yesterday condemned the attack. "Thus far, there are no reports of any Singaporeans who are directly affected by the explosion. Our embassy is in close contact with the Turkish authorities and will continue to monitor the situation closely," said the ministry.
The Istanbul governor's office said a probe was under way.
The Turkish authorities have, in recent weeks, detained several suspected ISIS members, with officials saying they were planning attacks in Istanbul.
The country is also waging an all-out assault on the outlawed Kurdistan Workers' Party, which has staged dozens of deadly attacks against members of the security forces in the south-east.
A Kurdish splinter group, the Freedom Falcons of Kurdistan, claimed a mortar attack on Istanbul's second international airport on Dec 23, which killed a female cleaner and damaged several planes.
Meanwhile, the banned ultra-left Revolutionary People's Liberation Party-Front has also staged a string of usually small-scale attacks in Istanbul over the last few months.
Businesses that rely on tourist dollars are feeling the heat from the string of terror attacks.
"Tourism had already dried up after last year's explosion, but after this, it's game over," said Ms Ayse Demir, 36, a shopkeeper at a local art and crafts shop.
AGENCE FRANCE-PRESSE, REUTERS, NEW YORK TIMES