The Turkish military has launched several air raids on PKK bases in northern Iraq in recent months.
In February, Turkish troops crossed into Iraqi territory, conducting an eight-day operation to destroy PKK targets.
Clashes between PKK fighters and Turkish troops have sporadically continued along Turkey's border with Iraq.
Self-determination
The Kurdish party took up arms in 1984 in an effort to secure Kurdish self-determination.
Tens of thousands of people have since been killed in fighting.
The group holds bases in the north of Iraq, which it uses as a launch pad for attacks against targets inside Turkey.
The Kurdistan Workers' Party leadership is believed to be hiding in the Qandil region, about 100 km from the Turkish border.
Turkey, like the US and the European Union, lists the PKK as a terrorist organisation.