At least nine people have been killed and scores wounded in a car bomb targeting a police headquarters in south-eastern Turkey.
The blast struck the building in Cizre, near the Syrian border, on Friday morning in the latest of a spate of similar attacks blamed on Kurdish militant groups.
Television footage showed much of the building reduced to burning rubble, sending huge plumes of smoke rising into the air.
Hospital sources said at least nine people were dead and 64 wounded, although there were fears the death toll could rise as recovery work continued.
There was no immediate claim of responsibility for the atrocity but local authorities blamed the Kurdistan Workers Party (PKK), a separatist group that is proscribed as a terrorist organisation by Turkey, the US and EU.
Its militants have been involved in almost daily clashes in the region since last July, when a ceasefire agreement with the government collapsed.
Isis has also launched a series of bombings and assassinations in the period, but has more frequently targeted tourists and landmarks in Istanbul and Ankara, compared to the insurgents’ focus on the government and security services.
The Turkish interior minister, Efkan Ala, accused the group of attacking a convoy carrying the main opposition party leader, Kemal Kilicdaroglu on Thursday.
The PKK was also suspected of being behind a spate of bombings in recent weeks, claiming responsibility for a blast that killed three officers at Elazig police headquarters on 18 August.
More than 600 Turkish security personnel and thousands of PKK militants have been killed in the insurgency since July, according to the state-run Anadolu Agency, while human rights groups say hundreds of civilians have also been killed amid a crackdown by the armed forces.
They are among at least 40,000 people, mostly Kurds, who have died since the rebels took up arms in 1984.
Amnesty International has condemned the series of “reckless and brutal attacks”.
“Those responsible for these crimes show contempt for the right to life and must be brought to justice,” said Andrew Gardner, the rights group’s Turkey researcher.
It comes amid continuing international alarm over the government’s response to a failed coup to oust President Recep Tayyip Erdogan.
Prime Minister Binali Yildirim said more than 40,000 people had been detained since the attempt on 15 July and about half have been formally arrested pending charges.
Those arrested include journalists and academics accused of supporting the Gulen movement, which authorities blame for the coup, and thousands of public sector workers have been suspended or sacked.
Michael Horowitz, a senior analyst at the Levantine Group, told The Independent PKK attacks had increased in both number and sophistication since the failed coup, which saw thousands of army personnel discharged.
Among the senior officers removed from their posts was General Adem Huduti, an alleged coup leader and the commander of Turkey’s Second Army – the division in charge of south-eastern Turkey and the borders with Iraq, Syria and Iran.
“The PKK is taking advantage of the weakening of the army to increase its campaign of attacks,” Mr Horowitz said.
“The PKK may see the aftermath of the coup as an unprecedented opportunity to put pressure on Erdogan’s government, and force him to resume negotiations.”
President Recep Tayyip Erdogan views Kurdish militias fighting Isis in Syria as an extension of the group, labelling groups backed by the US-led coalition “terrorists”.
Turkey has launched a major operation in the neighbouring country in recent days, sending tanks, special forces and allied Free Syrian Army rebels into Jarablus to drive back the so-called Islamic State.
But the offensive threatens to bring them into conflict with the US-supported Syrian Democratic Forces (SDF) – an alliance of mostly Kurdish opposition groups who have driven Isis out of swathes of north-eastern Syria.