Istanbul bomber entered Turkey as refugee from Syria, PM says

A woman places a candle at the site of Tuesday's suicide bomb attack at Sultanahmet square in Istanbul, Turkey January 13, 2016.[Photo/Agencies]

ISTANBUL - An Islamic State suicide bomber who killed 10 German tourists in the heart of Istanbul's historic district entered Turkey as a refugee from Syria and went undetected as he was not on any watch lists, Prime Minister Ahmet Davutoglu said on Wednesday.

The bomber, who blew himself up among groups of tourists on Tuesday near the Blue Mosque and Hagia Sophia, the top sites in one of the world's most visited cities, had registered with immigration authorities in the city a week ago.

Turkey has kept an open border to refugees from Syria's civil war and is now home to more than 2.2 million, the world's largest refugee population. But its border has also been used by foreign fighters seeking to join Islamic State or return from its ranks to commit atrocities abroad.

"This individual was not somebody under surveillance. He entered Turkey normally, as a refugee, as someone looking for shelter," Davutoglu told a news conference, adding he had been identified from fragments of his skull, face and nails.

"After the attack his connections were unveiled. Among these links, apart from Daesh, we have the suspicion that there could be certain powers using Daesh," he said, using an Arabic name for Islamic State.

Asked if Turkey planned retaliatory air strikes on Islamic State, Davutoglu said Ankara would act at a time and in a manner that it saw fit. He pointed out the Turkish military had hit Islamic State targets abroad after the Suruc and Ankara attacks.

But he said Russia's entry into the Syrian war was a complicating factor. Turkish war planes have not flown in Syrian air space since Turkey shot down a Russian fighter jet in late November, triggering a diplomatic row with Moscow.

"They (the Russian air force) shouldn't obstruct Turkey's fight against Daesh ... Right now unfortunately there is such a barrier," Davutoglu said. "Certain countries are in an obstructive attitude in terms of Turkey's air bombardments. They should either destroy Daesh themselves or allow us to do it."