A senior leader of the Kurdistan Workers Party (PKK) has threatened to topple the president of Turkey and his AKP party in an interviewed published as violence flared in Turkey's southeast.

“If [Turkish President Recep Tayyip] Erdogan defeats us, he will be able to defeat everyone on the side of democracy in Turkey,” said Cemil Bayik, speaking to the Times.

“We are the biggest obstacle in the way of his dreams. If Erdogan eliminates us, he will win."

He told the British newspaper, in an interview before Sunday's bombing in Ankara which the Turkish government blamed on the PKK, that "every order given to our guerrillas, is going to be legitimate."

“We want to topple Erdogan and the AKP. Turkey will never become a democratic country if Erdogan and the AKP are not toppled.”

The interview was published as violent clashes broke out between the Turkish security services and members of the Kurdish Civil Protection Units (YPS) in the southeastern city of Diyarbakir.

While fighting in the city had previously been located in the Sur district, the fighting on Monday evening took place in the central Baglar district.

One police officer and three militants were killed during the fighting, according to security sources.

The Baglar district administrator's office said that a curfew had been imposed in the district from 3am and would be maintained until further notice.

On Monday evening Erdogan warned that he would be cracking down on people and groups perceived to be encouraging the actions of the PKK.

A child looks on at Turkish security vehicles in Diyarbakir (MEE/Murat Bayram)

"It may be the terrorist who detonates bombs and pulls the trigger, but it is these supporters who enable them to achieve their goals," he said in a speech.

"Being an MP, an academic, journalist, writer or civil society group executive does not change the reality of that person being a terrorist."

The government claimed that around 45 PKK militants had been killed on Monday in air strikes on the group's stronghold in the Qandil mountains in northern Iraq.

Turkish military sources told Reuters that F-16 and F-4 jets destroyed two weapons depots and two Katyusha rocket positions.