Authorities were on Tuesday morning investigating what kind of explosive was used.
The Istanbul governor’s office said the authorities were investigating the type of explosive used and who might have been responsible for the attack. It said ten people were killed and 15 wounded but gave no further details.
“The explosion was very loud,” a worker at a nearby antiques store told reporters.
Cordon: Police secure the area, which is popular with tourists Lefteris Pitarakis/AP
Lefteris Pitarakis/AP
“We shook a lot. We ran out and saw body parts.”
Sultanahmet is Istanbul’s main sight-seeing area and includes the popular Topkapi Palace and Blue Mosque.
Erdem Koroglu, who was working at a nearby office at the time of the explosion, told NTV television he saw several people lying on the ground following the blast.
“It was difficult to say who was alive or dead,” Koroglu said. “Buildings rattled from the force of the explosion.”
Investigation: Police forensic experts work on the scene of the blast Murad Sezer/Reuters
Murad Sezer/Reuters
State-run agency Anadolu reported several police and medics were sent to the area.
Police sealed off the area, which includes a park that is home to an ancient Egyptian obelisk.
Turkey suffered two major bomb attacks last year.
More than 30 people were killed in an Islamic State (IS) suicide attack in the town of Suruc, near Turkey's border with Syria, in July.
And a pair of suicide bombs in October outside Ankara's main train station, detonated as people gathered for a peace rally, killed more than 100.
The prosecutor's office said that attack was carried out by a local IS cell.
Additional reporting by Press Association, Reuters and AP
