At least 10 people were killed and 15 other injured in a suspected suicide bombing at Istanbul's popular Sultanahmet tourist square on Tuesday morning, Turkish media reported.
Istanbul's governor's office announced that the explosion occurred at 10:20 a.m. local time near popular tourist spots Sultan Ahmet Camii (Blue Mosque) and Ayasofya (Hagia Sofia).
"I've never heard such a loud explosion in my life. It was very violent. Just after the incident I saw shocked tourists falling to the ground," an eyewitness told Anadolu Agency.
The suicide bomber reportedly blew himself up near a group of tourists, local media said. He allegedly targeted a group of foreign tourists. Security agencies suspect involvement of the Islamic State, ISIS/ISIL or Daesh. However, there was no official confirmation regarding ISIS's role.
Turkish President Reccep Tayyip Erdogan condemned the deadly blast, noting that the attack was carried out by a Syrian suicide bomber, according to BBC.
Kurdish Peoples' Democratic Party (HDP) leader Selahattin Demirtaş described the terror attack a brutal massacre. "We condemn the massacre in Sultanahmet. We will not stop following [the blast] so as not to let it be left in the dark and to reveal the ones responsible," he said in his condolence message, according to Dogan news agency.