"The general staff's military prosecution is continuing work ... on collecting evidence on the issue," the army spokesman, General Metin Gurak said in remarks posted on the army's website.

The allegations were reported by the Bugun daily last week in a further embarassment for the army whose members already face charges of involvement in a series of plots to discredit and overthrow the Islamist-rooted government.

Bugun quoted excerpts from wiretaps of a phone call in 2007 between two officers, in which one of them allegedly referred to Kurdish rebels as "our men" and lamented they were suffering heavy casualties because of the army's use of unmanned aircraft in security operations.

The officer asked for the drones to be re-routed or downed, while the other soldier responded "we will see what we can do," according to Bugun.

Gurak said the military authorities had launched an immediate investigation into the allegations after Turkey's intelligence service sent the wiretaps to the army in October 2007.

He rejected media criticism that the army was dragging its feet on the probe, citing difficulties in determining the identities of the soldiers and procedural complications in the judicial process.

The only drone used by the Turkish army at the time had been leased from Israel and was based at the southeastern city of Batman, Gurak said.

The Turkish army has fought the separatist Kurdistan Workers' Party (PKK) since 1984 when the group took up arms for self-rule in the Kurdish-majority southeast. The conflict has claimed some 45,000 lives.