A female member of the outlawed Kurdistan Workers’ Party was one of two suspected suicide bombers who killed 37 people in Ankara, according to Turkish security officials.
Unnamed officials told Reuters the woman joined the PKK in 2013 and was from the eastern Turkish city of Kars. The severed hand of a second, male attacker is said to have been found near the scene of the car bombing.
The explosives are reported to be the same as those used in an attack in February that killed 28 people, most of them soldiers.
Turkey has experienced an increase in violence since its ceasefire with the PKK collapsed in June 2015. In previous attacks, the militant group, which is seeking Kurdish autonomy, has targeted the Turkish military.
The two-year ceasefire ended when the PKK killed four Turkish police officers. The following month, Turkey bombed PKK camps in Iraq, with the PKK retaliating with a car bomb attack against Turkish troops.
After the latest attack in Ankara, Turkish warplanes bombed PKK camps in northern Iraq, following President Recep Tayyip Erdogan’s assertion that terrorism would be brought “to its knees”.
A curfew has been imposed in south-eastern town of Sirnak, where military operations against Kurdish militants are being carried out.
The PKK is considered a terrorist organisation by Turkey, the US and the EU.
In February, 28 people were killed in Ankara when a military convoy was targeted by bombers. The Turkish government blamed the PKK and the People’s Defence Units (YPG), Kurdish rebels who are fighting Islamic State in Syria and are backed by the US.
Turkey views the YPG as an affiliate of the PKK, but it has not managed to convince the US that this is the case.
Islamic State militants have been blamed for at least four bomb attacks on Turkey since June 2015, including a suicide bombing that killed 10 German tourists in Istanbul in January.
In October 2015, more than 100 people were killed in suicide bombings at a Kurdish peace rally in the Turkish capital.
Turkey is hoping to join the EU and last week agreed the broad outline of a deal on migrants with European leaders under which talks about membership will be brought foward.
With President Erdogan accused by his critics of taking Turkey in an increasingly authoritarian direction – exemplified by the seizure of the anti-government newspaper Zaman – EU membership over the next few years looks highly unlikely.