PKK militants killed two Turkish police officers in an attack overnight on a police station in southeast Turkey, security and hospital sources said on Thursday.

The attacks came one month ahead of a parliamentary election, which is expected to result in a comfortable third successive victory for Prime Minister Tayyip Erdogan's AK Party.

The outlawed Kurdistan Workers Party (PKK) militants opened fire with rifles on a guard post in front of the police station in the town of Silopi, near the border with Iraq.

The PKK ended a six-month ceasefire in February and there have been fears of rising violence before the election.

Jailed PKK leader Abdullah Ocalan has threatened "war" unless the government enters talks to end a 27-year-old separatist conflict after the June 12 election.

Police set up checkpoints on the outskirts of Silopi and conducted house searches in the town, while helicopters patrolled surrounding countryside in search of the militants, security sources told Reuters.

The second of the officers died after being flown by helicopter for treatment at a hospital in the main southeastern city of Diyarbakir.

In separate violent incidents overnight, unknown assailants threw petrol bombs at a supermarket in the eastern town of Elazig and at a post office in the southern city of Mersin. In the nearby city of Adana, a car was damaged in a small bomb explosion, broadcaster CNN Turk reported.

More than 40,000 people have been killed in the Kurdish conflict.

The PKK last week claimed responsibility for an ambush that killed one police officer and wounded another in the northern Black Sea province of Kastamonu Turkey after an election rally by Erdogan.

Reuters