Explosion kills four, injures 38 at central Istanbul

The city's governor reported that four persons were killed and 38 were injured in an explosion on Istanbul's well-known pedestrian Istiklal Avenue.

The explosion happened on Sunday around 4:20 p.m. (13:20 GMT), according to Istanbul Governor Ali Yerlikaya, who also tweeted the death toll.

It remained unclear what caused the explosion.

“There are strong suspicions that this was a suicide bomb, but we don’t have any official statement yet [on that],” Al Jazeera’s Sinem Koseoglu said from Istanbul.

In an early report, CNN Turk said that 11 persons had been hurt.

In one online video, passersby can be seen turning and fleeing as flames burst out and there is a loud blast.

A different piece of the video showed police, fire trucks, and ambulances in the area. Shops were reportedly closed, according to social media users.

The road is a busy street with restaurants and businesses that attract both tourists and residents.

According to the Turkish Red Crescent, blood was being sent to area hospitals. A broadcast embargo on coverage of the explosion was imposed by Turkey's RTUK regulator around an hour after it happened.

“My condolences to those who lost their lives in the explosion on Istiklal Avenue,” Mayor Ekrem Imamoglu said on Twitter.

Between 2015 and 2017, ISIL (ISIS) and the outlawed Kurdistan Workers' Party attacked Turkey with a series of deadly attacks (PKK).

According to Koseoglu of Al Jazeera, there haven't been any recent alerts about assaults in the city, thus the explosion comes as a surprise.

“But security measures have remained high in the area,” she said.

Security expert Murat Aslan told Al Jazeera that the explosion occurred in a fairly congested area with tight security in place.

“The police in general is on the highest level in this area,” he said.

“There are a lot of security cameras in the area. I think the police will identify exactly who did this and how he or she did this if it is a terror attack,” he added.