Six people were killed and 53 others were wounded on Sunday when an explosion rocked a busy pedestrian street in central Istanbul.
Ambulances raced to the scene on the packed Istiklal Avenue, which police had quickly cordoned off. The area, in the Beyoglu district of Turkey's largest city, had been crowded as usual at the weekend with shoppers, tourists and families.
Video footage obtained by Reuters showed the moment the blast occurred at 4.13 p.m. (1313 GMT), sending debris into the air and leaving several people lying on the ground, while others fled the scene.
"Efforts to defeat Turkey and the Turkish people through terrorism will fail today just as they did yesterday and as they will again tomorrow," President Recep Tayyip Erdogan told a news conference in Istanbul.
"Our people can rest assured that the culprits behind the attack will be punished as they deserve," he said, adding that initial information suggested "a woman played a part" in it.
"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," he added.
