ISIS 'Prime Suspect' in Istanbul Explosion That Killed At Least Ten

A police officer secures the area after an explosion near the Ottoman-era Sultanahmet mosque, known as the Blue mosque in Istanbul, Turkey January 12, 2016. Reuters/Kamal Aslan

The Islamic State militant group (ISIS) is being suggested as the likely perpetrator of the blast that left at least 10 people dead in Istanbul's historic Sultanahmet Square on Tuesday, according to Turkish analysts and security sources.

Two senior Turkish security officials told Reuters that there is a high probability that ISIS militants were responsible for the explosion near the Blue Mosque and Hagia Sophia landmarks in the country's largest city.

Doruk Ergun, security analyst at Turkish think tank the Center for Economics and Foreign Policy Studies (EDAM), said that the Islamic State militant group (ISIS) is the prime suspect for the attack as Turkey continues to increase its participation in efforts against the group in the country and in Iraq and Syria.

"The most likely culprit is ISIS," Ergun says. "The last few months have seen an increased risk of terrorism in Turkey, especially in the capital Ankara and other major cities."

"This increased risk is both the result of potential attacks from ISIS, as Turkey contributes more and more to the anti-ISIS coalition, and also potentially from PKK and other affiliated movements," he adds.

No group has yet claimed responsibility for the attack and other groups, such as the Kurdistan Workers' Party (PKK) and the leftist DHKP-C, have also conducted attacks in Turkey within the last year.

However, in October, ISIS claimed responsibility for the twin Ankara bomb blasts that struck a peace rally, leaving 102 people dead. It is also believed to have been behind the suicide bomb attack in the town of Suruc near the Syrian border, which targeted a group of Kurdish youth activists, killing 33 people.

The increased risk of extremism acts should have a significant impact on Turkey's economy and the tourism sector that has already been damaged by the crisis in relations with Russia and the attack in Ankara, says Ergun.

"We have already seen a drop in potential tourists that would come to Turkey this year due to the increased security situation," he says. "Now, an attack in the heartland of the country in Istanbul, in the touristic neighbourhood, is definitely going to increase this risk. So we are going to see in the coming months, economic costs resulting from this attack as well."

On Tuesday, Germany moved to warn its citizens from visiting Istanbul's tourist sites following the attack.

"Travellers in Istanbul are strongly urged to avoid for now large groups of people in public places as well as tourist attractions," the foreign ministry said. It added that there could be "political tensions as well as violent clashes and terrorist attacks across the country."

Turkey, a NATO member, is participating in the U.S.-led coalition against ISIS in Syria and Iraq, as it continues to combat an insurgency by Kurdish militants in the country's southeastern regions.