Six people were killed and at least 81 injured in what is being treated as a terror attack after a bomb exploded on a crowded street in Istanbul today.
Harrowing footage shows bodies strewn in the street following the huge blast which tore through a popular shopping district of Istiklal Avenue.
In one video, an overturned pram can be seen lying on the pavement with children appearing to be among those injured.
This evening, Vice President Fuat Oktay updated the wounded toll from 53 to 81, with two in a serious condition.
He said: "We consider it to be a terrorist act as a result of a female attacker detonating the bomb."
A female suspect has since been arrested after police released a CCTV image of a woman fleeing the scene moments before the explosion, wearing a hijab, a leather jacket and camouflage combat trousers.
Turkey’s Interior Minister Süleyman Soylu has since confirmed the suspected culprit has been arrested.
“The person who dropped the bomb was detained by our General Directorate of Security,” he told TRT Haber.
Speaking before his departure to the G-20 summit in Indonesia, Turkish President Recep Tayyip Erdoğan called the explosion a “treacherous attack” and said its perpetrators would be punished.
Erdogan did not say who was behind the attack, but said it had the "smell of terror" without offering details.
In March 2016, a suicide bombing on the same street killed five people.
It remains unclear what caused today's explosion, although footage reportedly showed a woman dropping a bag on a bench shortly before the blast.
"Unfortunately, in the explosion that took place on Istiklal Street today, the number of dead increased to 6 and the number of injured to 53", Istanbul governor Ali Yerlikaya said.
"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."
A manager of a restaurant near where the bomb went off said he heard the explosion and saw people running.
The dozens of customers inside his restaurant, including women and children, panicked and screamed.
The manager, who spoke on condition of anonymity because of the sensitivity of the situation, said he closed his restaurant's shutters, fearing there might be another explosion, and tried to calm the customers down.
After about 15 to 25 minutes inside, he saw police on the avenue and organized the customers and his staff to leave in small groups.
A horrifying video shows flames erupting and a loud bang heard as pedestrians ran away from the blast, which happened at around 4.20pm local time (1.20pm GMT).
Numerous foreign governments offered their condolences, including neighboring Greece with which relations are tense.
Prime Minister Kyriakos Mitsotakis said he was "shocked and saddened by the news of the heinous attack."
NATO Secretary General Jens Stoltenberg tweeted: "Shocking images from Istanbul. My thoughts and deepest condolences to all those affected & to the Turkish people. NATO stands in solidarity with our Ally #Türkiye."
French President Emmanuel Macron noted that the attack came exactly seven years after Islamic State extremists killed 130 people at Paris cafes, the Bataclan theater and France's national stadium.
He said: "On such a symbolic day for our nation, as we are thinking of the victims who fell Nov. 13, 2015, the Turkish people were hit by an attack on their heart, Istanbul.
"To the Turks: We share your pain. We stand at your side in the fight against terrorism."
The Turkish Football Federation announced that tonight's match between Beşiktaş and Fraport TAV Antalyaspor had been postponed to a later date following the explosion.
İstiklal Caddesi is a crowded thoroughfare popular with tourists and locals, lined by shops and restaurants that tourists often visit but also where thousands of Turks go to work, eat, get a coffee, pray and meet people.
Footage sent to Middle East Eye from the scene showed the bodies of one child and one man mortally wounded.
CNN Turk reports that the explosion was also heard from the surrounding districts of Beşiktaş and Şişli due to its high intensity.
And reports in Turkish media that say there were dozens of gunshots around the shops in Sishane, about a half-hour walk south-west of the initial blast.
After the explosion, the police closed the entrances and exits to Istiklal Street and police gradually evacuated the side streets. The injured were taken to Taksim First Aid and Okmeydanı.
Koseoglu said the explosion comes as a shock, as there have not been any recent warnings over attacks in the city.
Bellingcat, the fact-checking and open-source intelligence agency, has shared CCTV footage from today which shows a bag left on a bench that seems like a possible source of the explosion.
The Turkish media regulator, Radio and Television Supreme Council, has imposed a ban on sharing footage of the explosion or reports except for government statements.
A statement by the Istanbul Chief Prosecutor's Office said it has opened a probe into the incident.
"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," the statement said.
It continued: "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."
Live network data show that social media platforms Twitter, Instagram, YouTube and Facebook have been restricted in Turkey.
The Supreme Board has imposed similar bans in the past, following attacks, accidents and some political issues.
At the boulevard's northern end is Taksim Square, the symbolic heart of the modern city and the scene of often-violent protests in recent years. Its southern end is Tünel Meydanı and the district of Galata.
Turkey was the target of a series of terror attacks that peaked in 2016 with an assault on Istanbul’s main international airport carried out by the Islamic State.
The horrific attack injured hundreds and killed 41 people, at least 13 of whom were foreign nationals.
On New Year's Day in 2017, an attack by ISIS at the Reina nightclub in Istanbul killed 39 people.
The string of deadly attacks hugely impacted Turkey’s tourist industry, rocking the country’s economy.
