At least six people have been killed and 81 wounded in an explosion in a busy area of central Istanbul, Turkish authorities have said.
The blast happened at about 16:20 local time (13:20 GMT) on Sunday on a shopping street in the Taksim Square area.
A suspect has now been arrested, the interior minister said.
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.
Justice Minister Bekir Bozdag told Turkish media a woman had sat on a bench in the area for more than 40 minutes, leaving just minutes before the blast took place.
On Monday morning, Interior Minister Suleyman Soylu said a person suspected of having left the bomb had been arrested by police, and accused the Kurdistan Workers’ Party (PKK) of responsibility.
The PKK is a militant group which 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.
Government minister Derya Yanik wrote in a tweet that a government ministry employee and his young daughter were among the victims.
