Separatist Kurdish rebels killed seven soldiers in Turkey's east and along the Iraqi border, officials said yesterday, underscoring the mounting violence in the 26-year insurgency.

In one of their bloodiest assaults this year, the Kurdistan Workers' Party (PKK) militants targeted a military unit near the Iraqi border overnight with rocket launchers and assault rifles, killing six soldiers, military sources said.

The Turkish army said in a statement that nine soldiers had been lightly wounded in the attack on the unit near the border town of Cukurca, while Prime Minister Recep Tayyip Erdogan put the figure at 15.

"The region has been reinforced with helicopter gunships and troops. Operations are underway," the arm's statement said.

The PKK claimed that the attack, which started at 2 a.m. (2300 GMT), had killed 13 soldiers and said there were no casualties among rebel ranks.

PKK's foreign relations chief Roz Walat, based in Iraq where the rebels have rear bases, added that his fighters had also destroyed Turkish mortars and canons before fleeing.

In a separate attack, PKK rebels fired on a group of soldiers on a security sweep near Gurpinar in the eastern province of Van Tuesday, killing one of them, local military sources said.

In Ankara, Mr Erdogan said his government was determined to crush the rebels.