Diyarbakir - Kurdish rebels armed with machine-guns and rocket launchers attacked a security complex in southeastern Turkey overnight, triggering fierce fighting that left about 30 people dead, local sources said on Monday.
Ten soldiers were killed and seven wounded in the attack in the province of Sirnak, the local government said, while other local sources said about 20 members of the outlawed Kurdistan Workers' Party (PKK) were also killed.
Provincial governor Vahdettin Ozkan said the militants had attacked the security complex at Beytussebap late on Sunday, killing nine members of the security forces and wounding eight. His office later said that one of those wounded had died.
Police and soldiers returned fire, triggering fierce clashes.
The PKK has stepped up its assaults against Turkish security forces in recent months, with Turkish officials and the local media linking the surge to the conflict raging in neighbouring Syria.
Last month, 10 people were killed in a car bomb attack blamed on the separatist Kurds in the southeastern city of Gaziantep.
Turkish Prime Minister Recep Tayyip Erdogan had threatened military intervention if the Kurdish rebels set up bases in Syria.
Some government officials believe that Damascus - once backed by Ankara - is helping the PKK in retaliation for Turkey's support for rebels fighting President Bashar Assad.
The PKK, considered a terrorist group by Turkey and much of the international community, took up arms in Kurdish-majority southeastern Turkey in 1984, sparking a conflict that has claimed about 45 000 lives.