News of the violence came just ahead of a cabinet meeting during which the government is expected to discuss a tough response to violence by Kurdistan Workers' Party (PKK) rebels holed up in bases in neighbouring northern Iraq.

As the cabinet convened, the Turkish foreign ministry summoned the Iraqi and US ambassadors in Ankara for talks on curbing the rebels who cross into Turkey from their bases in the Kurdish-held north of Iraq to engage in anti-government violence.

In the latest clash, the two PKK rebels were killed in the town of Gercus in Batman province in an operation overnight on their hide-out, after the pair opened fire on an armoured police vehicle and wounded an officer, the sources said.

A second policeman was also wounded in the operation and he later succumbed to his injuries at hospital.

The latest casualty brought to 15 the death toll among Turkish security forces in five days.

Two soldiers were wounded in a clash Monday with PKK rebels during a security operation on rural ground in the eastern province of Tunceli, security sources said.

In a house raid Monday in Diyarbakir, the biggest city in the southeast, police seized 27.4 kilos (54.3 pounds) of plastic explosives, which they belive were intended for attacks in urban centres, along with a substantial cache of ammunition, local sources said.

"We have so far tried to handle this issue with patience... to resolve this problem with a democratic approach... (but) these are not acts that one can put up with," Turkish Prime Minister Recep Tayyip Erdogan said in a televised speech on Sunday.

"I have to say that the cabinet meeting tomorrow (Monday) is poised for many things," he said.

In Ankara, the top anti-terrorism body comprised of senior ministers, generals and security officials, held its second meeting in two days to review the situation ahead of the cabinet meeting.

No statement was issued after the meeting, which was also attended by Erdogan.

A senior Turkish diplomat told AFP that Iraqi ambassador Sabah Umran and US Ambassador Ross Wilson were called into the foreign ministry for talks with undersecretary Ali Tuygan on PKK violence and rebel presence in northern Iraq.

Turkey says thousands of armed PKK militants have found refuge in northern Iraq since 1999, when the group declared a unilateral ceasefire after the capture of its leader, Abdullah Ocalan.

Much to Ankara's frustration, both Baghdad and Washington have been reluctant to take military action against the PKK, arguing that their forces are swamped by violence in other parts of conflict-torn Iraq.

The issue has become of increasing importance for Ankara in recent months as clashes have escalated between the PKK and the army since the rebels called off their truce in June 2004.

The rebels have carried out several bomb attacks in urban centres this year.

More than 37,000 people have been killed 1984 since the PKK, listed as a terrorist group by Turkey, the European Union and the United States, picked up arms for Kurdish self-rule in the southeast.