The court in the southeastern town of Diyarbakir charged Kamil Atak, the former mayor of Cizre, in Sirnak province, with murder and belonging to an illegal organisation, said the source who asked not to be named.

Atak, who was remanded in custody, was the second suspect to be charged after his own son following the excavation of nearly 20 suspected human bones close to a village near Cizre last week.

The dig was carried out as part of a probe launched in February after media published statements by a defector from the outlawed Kurdistan Workers' Party (PKK) who claimed that several people were killed by security forces at the height of the group's separatist campaign during the 1990s.

He claimed the bodies were were thrown into pits filled with acid or buried along the road between Cizre and the nearby town of Silopi.

On Monday, police arrested an army colonel -- the commander of the paramilitary police in the central city of Kayseri -- who was based in Silopi in 1990.

Atak and his son were implicated after an unidentified witness told the prosecutor in charge that former mayor had handed over several people suspected of aiding the PKK to members of another outlawed group, the Islamist Turkish Hizbullah, who in turn killed them.

The Turkish Hizbullah, which has no known links to its Lebanese namesake, was set up in the early 1990s as a reaction to the PKK and is believed to have been used by Turkish authorities against the rebels.

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.