Turkish officials have blamed the Kurdistan Workers' Party (PKK) for the blast. 

The PKK is a militant group that calls for an independent Kurdish state within Turkey. The EU and the US regard it as a terrorist organisation. No one has so far claimed responsibility for the blast. 

Vice President Fuat Oktay earlier said the blast was thought to be a terrorist attack carried out by a woman.

President Recep Tayyip Erdogan said the perpetrators would be punished.

Speaking at a news conference in Istanbul, he condemned what he called the "vile attack" and said "the smell of terror" was in the air.

Eight people were killed and at least 80 injured. Five prosecutors have been assigned to investigate the explosion.

BBC