An explosion in a central area of Istanbul claimed at least six lives and wounded another 53 people on Sunday, according to Turkish authorities. The blast, caught on tape by shocked onlookers, rattled the heart of Taksim Square around 4:20 p.m. local time. The eruption soared in an orange ball of flame on a pedestrian street in the city’s tourism district, causing hundreds of shoppers to turn and flee. “I saw three or four people on the ground,” one onlooker, Cemal Denizci, told AFP. “People were running in panic... There was black smoke. The noise was so strong, almost deafening.” State officials believe the attack to have been an act of terrorism, perpetuated by a woman. “We consider it to be a terrorist act as a result of an attacker, whom we consider to be a woman, detonating the bomb,” Turkish Vice President Fuat Oktay said. Istanbul’s Public Prosecutor’s Office is currently investigating the situation. The last time the area was struck by terrorism was in 2015 and 2016, when Islamic militant groups and Kurdish separatists targeted the region, according to Reuters.