ISTANBUL, Turkey, Jan. 12 (UPI) -- At least 10 people died after an explosion Tuesday morning at the popular tourist Sultanahmet district of Istanbul, Turkey, near the city's historic Blue Mosque.
"I condemn the terror incident in Istanbul assessed to be an attack by a suicide bomber with Syrian origin," Erdogan said during a speech broadcast on live television. "Unfortunately we have 10 dead including foreigners and Turkish nationals ... There are also 15 wounded."
Some officials have said the bomber was linked to the Islamic State terror group.
The United States also condemned the attack Tuesday.
"We extend our deepest condolences to the families of those killed, and wish a quick and full recovery to those injured," said Bureau of Public Affairs spokesman John Kirby. "The United States reaffirms our strong commitment to work with Turkey, a NATO Ally and valued member of the Counter-ISIL Coalition, to combat the shared threat of terrorism."
"We reaffirm our support for these negotiations and for Djibouti's commitment to strengthening inclusive governance and development," he continued.
An investigation into the blast has been launched. The surrounding area was shut down by police.
"I've never heard such a loud explosion in my life," shop owner Sener Ozdemir, 45, told Anadolu Agency of the blast near Sultanahmet Square. "It was very violent. Just after the incident I saw shocked tourists falling to the ground."
Turkey has faced increased violence in recent months generated by the Islamic State and after a ceasefire broke down between the Turkish government and PKK Kurdish rebel militants -- which led to airstrikes by Turkey and bombings by rebels.