A suicide bomber suspected to be from Syria set off a blast in the heart of Istanbul's tourist district Tuesday, officials said, killing at least 10 people and injuring 15 others.

According to Reuters, the terrorist triggered an explosion in Sultanahmet Square, near the Blue Mosque and Hagia Sophia, one of the most popular tourist sites in the world renowned city.

Sources from Prime Minister Ahmet Davutoglu's office said the majority of victims in the attack were German tourists. Chancellor Angela Merkel was said to have been informed and offered condolences.

Deputy Prime Minister Numan Kurtulmus said the bomber's remains were used to identify him as a Syrian national born in 1988.

No terrorist organization has yet come forward to claim responsibility for the attack, but Turkish officials have pointed to the Islamic State for recent bombings in the country. Kurdish militants and left-wing radicals have also carried out attacks.

Turkish President Recep Tayyip Erdogan strongly condemned the attack and said the country would continue to stand strong against terrorism.

"This incident has once again shown that as a nation we should act as one heart, one body in the fight against terror," Tayyip Erdogan said during a live television broadcast. "Turkey's determined and principled stance in the fight against terrorism will continue to the end."

The normally packed square, also known as the Hippodrome of Constantinople, was sealed off in the aftermath of the explosion, the center of which was located near a local tram station next to the landmark Obelisk of Theodosius. Bodies littered the ground in a scene that one police officer described as "unimaginable."

Tour operator Kursat Yilmaz heard the blast when the bomb went off.

"At first we thought it was percussion bomb, it was so loud. They attacked Sultanahmet to grab attention because this is what the world thinks of when it thinks of Turkey," Yilmaz said.

Turkey, a NATO member and one of the nations in the U.S.-led coalition against ISIS, has frequently been targeted by the terror group, who operate in the neighboring countries of Syria and Iraq. Two senior security officials said it was very likely the group was responsible for Tuesday's attack.