Turkey's state-run news agency says security forces have killed 12 Kurdish rebels in clashes in the southeast, raising the two-day death toll in the fighting to 18.

The Anadolu Agency says 12 Kurdish fighters were killed Thursday in an operation that was backed by air power. That came a day after Kurdish rebel raids on a paramilitary post and a military installation near the border with Iraq sparked clashes that left three soldiers and three rebels dead.

There's been a surge in violence in recent months between Turkish forces and rebels from the Kurdistan Workers' Party, or PKK, which is fighting for autonomy for Kurds in southeast Turkey.

Tens of thousands of people have been killed since the PKK took up arms in 1984.