People fled after the explosion on Istiklal Avenue in Taksim district. A video posted online shows flames erupting and a loud bang. Istanbul Governor Ali Yerlikaya tweeted: “According to initial information, four people died and 38 were injured in the explosion that occurred on Istiklal Street. “Our wounded are being treated. “We wish God’s mercy to those who lost their lives and a speedy recovery to the injured.” State broadcaster TRT showed video of ambulances and police heading to the scene. Social media users said shops were closed and the boulevard was closed. The cause of the explosion was not immediately known. Five prosecutors have been assigned to investigate the explosion, the state-run Anadolu news agency reported. Turkey’s RTUK regulator imposed a broadcast ban on coverage of the explosion about an hour after the explosion. It prevents broadcasters from showing video from the time of the explosion or its aftermath. Image: People run away from the explosion Image: Members of the security forces stand near the scene Istiklal Avenue is a pedestrian street popular with tourists and locals and is lined with shops and restaurants. Turkey suffered several deadly bombings between 2015 and 2017 by Islamic State and outlaw Kurdish groups.