A massive explosion ripped through Istanbul's popular pedestrian Istiklal Avenue on Sunday killing at least six people and leaving more than 50 injured in what President Recep Tayyip Erdogan hinted may be a terrorist attack. A chilling video has surfaced on Twitter that captures the moment the explosion occurred.
Other videos posted on social media show bodies strewn on the ground as emergency workers scrambled to evacuate people. When the explosion occurred at around 4:20 pm local time, the avenue lined with shops and restaurants was crowded with tourists and residents. No terrorist outfit has yet claimed responsibility for the explosion.
Horror Sunday in Istanbul
According to local media reports, four people died on the scene, while two succumbed to their injuries in the hospital after the massive explosion ripped through the Taksim Square area. As of now, 53 others have been injured, with more than a dozen seriously wounded. It is feared casualties will increase overnight.
Erdogan denounced the incident as 'a vile attack' and said the perpetrators would be punished as he hinted that it could be a terrorist attack.
"Our nation should be sure that the perpetrators of the incident on Istiklal Street will be punished as they deserve. We cannot say for sure that it is a terror attack but there is a smell of it as far as I know. There is a woman who has taken part in the incident," he said in a televised statement.
"Efforts to take over Turkey and the Turkish nation through terrorism will not reach its goal," he added.
A video that was uploaded online shows pedestrians turning and fleeing as flames burst out and there was a loud bang. Other videos showed the aftermath of the explosion with multiple people lying around and rubble covering the pavement.
Earlier Istanbul governor Ali Yerlikaya said: "According to initial reports, 4 people lost their lives and 38 were injured in the explosion that took place on Istiklal Street. Our wounded are being treated.
"We wish God's mercy on those who lost their lives and a speedy recovery to the injured. Developments will be shared with the public."
Police immediately cordoned off the area as there were a lot of people there on Sunday afternoon, while helicopters were seen flying over the city's core and sirens sounding. "I was 50-55 meters away, suddenly there was the noise of an explosion. I saw three or four people on the ground," witness Cemal Denizci, 57, told AFP.
"People were running in panic. The noise was huge. There was black smoke. The noise was so strong, almost deafening," he said.
Istikal Avenue was earlier attacked by a suicide bomber in 2016. Kurdish separatists, Islamist terrorists, and other groups have previously threatened Istanbul and other Turkish cities.
Users on social media claimed that the avenue was closed and that stores had pulled down the shutters.
"My condolences to those who lost their lives in the explosion on Istiklal Avenue," Mayor Ekrem Imamoglu wrote on Twitter.
One child and one father were reportedly found dead at the scene, according to a video sent to Middle East Eye.
"There are strong suspicions that this was a suicide bomb, but we don't have any official statement yet," Al Jazeera's Sinem Koseoglu said from Istanbul.
The fact-checking and open-source intelligence agency Bellingcat posted CCTV footage from today that appears to indicate a bag left on a bench as a potential explosion source.
According to a statement from the Istanbul Chief Prosecutor's Office, video of the explosion cannot be shared. "Due to the explosion in Istiklal Street today, an investigation has been started by our Istanbul Chief Public Prosecutor's Office and five public prosecutors have been appointed for that purpose.
"In addition, a broadcast ban was issued by the Istanbul Criminal Court of Peace for all visual and audio news and social networking sites related to the explosion."
Murat Aslan, a security analyst, told Al Jazeera that the place where the attack took place is a civilian and highly crowded area with maximum security precautions.