In the latest sign of surging violence in the region, Kurdistan Workers' Party (PKK) rebels, armed with rockets and assault rifles, attacked a military unit in a rural area near Dogan village in Siirt province, the general staff said in a statement on its website.

Four soldiers were wounded in the initial fire and two later died in hospital.

Another group of rebels launched a simultaneous attack against village guards -- Kurdish militia armed and paid by the government to fight the rebels -- near the village, killing three of them.

Twelve PKK rebels were killed in the ensuing operation backed by artillery fire and helicopter gunships, the statement added.

The Turkish government has come under pressure to take tougher measures against the PKK amid a recent dramatic rise in rebel attacks on Turkish targets as part of a 26-year insurgency in the Kurdish-majority southeast.

In their bloodiest attack in two years, PKK killed 12 soldiers near the Iraqi border earlier this month. Last week, five soldiers and a civilian died in a bomb attack in Istanbul claimed by the rebels.

Amid public outrage over Turkish army losses which has topped 60 since March, the military has carried out retaliatory air strikes and ground incursions against PKK rear bases in neighbouring northern Iraq.

US intelligence on rebel movements has been crucial for Turkish cross-border strikes, but media reports suggest that Ankara is unhappy over not receiving real-time intelligence from their US counterparts which would allow them to successfully hit targets.

Furthermore, Prime Minister Recep Tayyip Erdogan said Monday, after meeting US President Barack Obama at the G20 summit in Canada, that he expects Washington to "take more determined steps in the struggle against terrorism...that goes beyond intelligence-sharing."

He did not give details, but his deputy Cemil Cicek said Wednesday that among Ankara's demands were the arrest of senior PKK leaders hiding in northern Iraq.

"The United States is, to a certain extent, responsible for security in northern Iraq.... There is a lot that the United States, the central government in Iraq and Kurdish authorities controlling northern Iraq can do on this," Cicek was quoted by the Anatolia news agency as saying.

He also urged EU countries to clamp down on rebel activities on their soil. The PKK, blacklisted by Ankara and much of the international community, including the EU, has an extensive support network among Kurdish immigrants in Europe.

Fresh measures against the PKK were being discussed in a three-way committee set up by the US, Iraq and Turkey in 2008 to combat the rebels, Cicek said, but refused to give details.

The escalating PKK violence has also cast a shadow over government efforts to boost Kurdish freedoms and investment in the impoverished southeast in return for the PKK to lay down arms.

Earlier this month, the PKK said it was ending a unilateral ceasefire in place since April 2009 because of continuing Turkish military operations, and last month jailed PKK leader Abdullah Ocalan said he was abandoning efforts to seek peace with Turkey.

Some 45,000 people have been killed since the PKK took up arms against Ankara in 1984 for self-rule in the southeast, sparking a conflict that has led to gross human rights violations on both sides, displaced thousands and impoverished the region.