Gendarmerie sergeants Ali Kaya and Ozcan Ildeniz and Veysel Ates -- a former member of the Kurdistan Workers' Party (PKK) described in the indictment as having turned informer since 2004 -- are accused of staging the November 9 bomb attack against a bookstore in Semdinli, in Hakkari province.

The prosecution described the three as rogue elements within the security forces targeting the outlawed Kurdistan Workers' Party (PKK), whose rebels have led a bloody campaign since 1984 for Kurdish self-rule in the region.

They are charged with "committing acts aimed at destroying the unity of the state and the integrity of the country," in addition to murder and forming a criminal organisation.

In Thursday's opening session in a tiny, packed courtroom in this eastern city, Kaya denied any role in the bombing and laid the blame on the PKK.

"We did not place any bombs," he said, insisting that "there was no involvement of security bodies such as the army, the police or the secret services -- or of the mafia or criminal gangs."

In Friday's session, he answered questions from lawyers representing the owner of the bookstore on how gendarmerie intelligence units conducted covert operations in the region.

Asked whether he had information on any of the unsolved murders that were prevalent in the southeast at the height of the PKK rebellion, Kaya said: "No, I do not."

Thousands of people, mainly Kurdish dissidents, are believed to have been summarily executed in the region during a heavy military reponse to the PKK campaign.

More than 37,000 people have been killed in the fighting between the Turkish army and the PKK, with both sides accused of gross human rights violations.

The court was expected to hear testimony from Ildeniz and Ates later Friday.

The bombing of the bookstore owned by a former PKK rebel killed one person and sparked deadly riots in remote Hakkari, which abuts Iraq and Iran.

The prosecutor described the attack as an act of provocation aiming to stir unrest among Kurds, discredit the government and undermine Turkey's bid to join the European Union.

Kaya, Ildeniz and Ates, who reportedly threw the bomb, were nearly lynched by an angry mob at the site of the blast.

Weapons, hand grenades, a sketch of the bookshop and a list of names, including that of the shopowner, were found in the car the three tried to flee in after the explosion.

The Van trial is widely seen as a test for Ankara to prove its commitment to the supremacy of the law and shed light on rogue elements in the security forces, accused of murder, extortion, kidnappings and drug smuggling.

The prosecution had also called for an investigation into the commander of the Turkish land froces, General Yasar Buyukanit, for alleged illegalities in combating the PKK during his term as a regional commander in the southeast in the 1990s.

The army vehemently rejected the allegations and urged the government to punish "those behind this onslaught... aimed at eroding (the credibility of) the Turkish armed forces."

The prosecutor who drew up the indictment was sacked last month by a panel of his peers for having exceeded the limits of his jurisdiction.