Six people were killed and around 80 injured in a bomb explosion in the Turkish capital Ankara.
The explosion on Tuesday evening hit the busy Ulus area of the city at a bus stop outside a block of offices just as the streets were full of commuters heading home.
Prime Minister Recep Tayyip Erdogan told reporters at the scene of the blast that four Turks and a Pakistani national were killed in the initial blast. Health Minister Recep Akdag said that around 80 were injured.
One of the injured later died in hospital, bringing the death toll to six.
The Pakistani killed was a member of a Pakistan armed forces delegation in Turkey to attend a military fair.
Television footage showed widespread damage to buildings near the blast with many windows blown out.
The NTV private television station quoted police sources saying they had found traces of A-4 plastic explosives. Police immediately labelled the rebel Kurdish Workers' Party (PKK) as a prime suspect.
In the past two months, police have seized some 200 kg of A-4 plastic explosives during raids around the country on PKK suspects. The explosives were smuggled into Turkey from neighbouring Iraq.
Witnesses said they had seen a suspicious package left at a bus stop at the scene of the blast, but it was not clear whether the blast was caused by a suicide bomber or set off by remote control.
NTV reported that seven people had been taken into custody in the first two hours following the explosion.
The PKK began operations in the early 1980s with the aim of carving out an independent Kurdistan in south-east Turkey. The group is listed as a terrorist organisation by the US and the European Union.