ISTANBUL — An explosion shook a bustling pedestrian thoroughfare in central Istanbul on Sunday, killing at least six people and wounding dozens, President Recep Tayyip Erdogan said.

Erdogan attributes the explosion to a “bomb attack” He stated that the perpetrators would be punished without naming any particular group. Before he flew to Indonesia for Group of 20 summit, he spoke to reporters at the airport. He said that preliminary findings had suggested that a female was involved, but did not give further details.

“Efforts to make Turkey and the Turkish nation surrender by terror will not reach their aim today, as they did not in the past,” He stated.

According to state-run Anadolu news agency, Vice President Fuat Oktay said that the government believed that the explosion was terrorist and that a woman had set off a bomb.

He claimed that four people were killed on the spot, and two died in hospital. He added that at least 81 people were injured and two are in critical condition.

The blast hit Istiklal Avenue, a short walk from Taksim Square and one of the city’s busiest areas for shopping, tourism and transit. The area may have seen even more people because of a soccer match scheduled for Sunday night. The game has been canceled.

Social media videos showed an orange fireball rising out of the street, panicking people and running away from the area. Others captured the scene with video cameras, which showed many people lying on the ground with serious injuries, some of whom were covered in blood but not moving.

An on-scene TV reporter said that he saw at least five people injured but still walking and at least four lying on the ground.

Fire trucks and ambulances raced to the scene, while a helicopter hovered overhead. The police sealed off the area. Some nearby stores had temporarily closed their doors after the blast but were reopened to people in need of shelter.

Carlotta Gall Contributed reporting