The court in Diyarbakir, the regional capital of the mainly Kurdish southeast, ordered two men remanded in custody on charges of involvement in extrajudicial killings, said the source, who requested anonymity.

A third man was later jailed pending trial on a murder charge.

All the suspects were former militants of the separatist Kurdistan Workers' Party (PKK) who later became informers against the rebel group, which has been fighting a 24-year armed campaign for self-rule.

Their arrests were linked to the excavation of 20 fragments of bone and tissue in recent digs in the the neighbouring province of Sirnak.

Three other people have already been charged in connection with the discovery, one of them a colonel who headed paramilitary troops stationed in Cizre town in Sirnak in 1993-1996.

The arrests came as the local prosecutor ordered a dig near the small village of Karacali, near Diyarbakir, on allegations that two people were buried there after being killed by the intelligence unit of paramilitary troops, JITEM, for alleged links with the PKK.

The claim came from Abdulkadir Aygan, a PKK rebel-turned-informer, now based in Sweden, who earlier this year told the Turkish press that he had worked with JITEM and claimed to have witnessed the murders of people suspected of links with the rebels.

His remarks led a prosecutor in Diyarbakir to launch a probe in February into allegations that Kurds were summarily killed in the 1990s, at the peak of the PKK's armed campaign.

The PKK took up arms for Kurdish self-rule in 1984, triggering a conflict with the Turkish state that has left 44,000 dead, displaced thousands and led to allegations of gross human rights violations by both sides.

Over the past 10 years the bodies of four missing people have been exhumed in the region, the most recent in 2005 by a roadside.