A Kurdish militant group that has carried out a string of attacks in Turkey this year on Sunday claimed a bombing on the south-eastern city of Diyarbakir that killed 11.

The claim by the Kurdistan Freedom Falcons (TAK), seen as an splinter group of the better-known Kurdistan Workers Party (PKK), came after a news agency affiliated to ISIS jihadists said they staged the strike.

The TAK issued a statement on its website saying the suicide bombing was executed by one of its militants named Kamal Hakkari.

It was a response to the "murderous policies" and "inexorable pressure" of the government in the mostly Kurdish southeast of the country, the statement said, vowing more TAK attacks against the "fascist Turkish state".

Turkish Prime Minister Binali Yildirim had blamed the attack Friday close to a police headquarters on the PKK.

But the US-based SITE Intelligence Group cited an "insider source" for the ISIS-affiliated Amaq news agency as saying "fighters from the Islamic State detonated an explosives-laden vehicle".

The local governorate in Diyarbakir on Saturday then issued a new statement insisting the bombing was carried out by the PKK, saying this conclusion was based on intercepted radio conversations.

It said that the three tonnes of explosives used in the bombing were activated by a PKK operative with the codename "Kemal".

The pro-Kurdish People's Democratic Party (HDP) said six of its MPs, including its co-leaders, had narrowly escaped injury in the attack as they were being held in the police complex following their detention overnight.

Without directly saying its MPs were the target, it noted that the minibus packed with explosives had blown up early following an alert from a taxi driver and called for the full facts to be revealed.

Reports said a local politician from the HDP-linked Democratic Regions Party (DBP), Recai Altay, who was being detained in the complex, was killed in the attack.

The TAK statement said it was "saddened" that Altay, "who was not a target", had lost his life.

The TAK had already claimed three major attacks this year in Turkey.