STORY: At least six people were killed and 81 others wounded when an explosion rocked a busy pedestrian street in central Istanbul on Sunday.
Video footage obtained by Reuters showed the moment the blast occurred, sending debris into the air and leaving several people lying on the ground, while others fled.
Ambulances raced to the scene, which police had quickly cordoned off.
The area, in Turkey's largest city, had been crowded as usual with weekend shoppers, tourists and families.
Turkish President Tayyip Erdogan stopped just shy of calling it a terrorist attack.
"It would be wrong to say this is undoubtedly a terrorist attack, but the initial developments and initial intelligence from my governor is that it smells like terrorism.”
Nobody has claimed responsibility for the blast.
Istanbul and other Turkish cities have been targeted in the past by Kurdish separatists, Islamist militants and other groups, including in a series of attacks in 2015 and 2016.