Istanbul - Turkish investigators have found bones, potentially the remains of victims of illegal executions, as part of a major search of a group of wells in south-eastern Turkey, newspapers reported Tuesday.

The search has opened up a group of so-called "death wells" where a secret unit within the Turkish police force is believed to have thrown the corpses of "disappeared" militants from the outlawed Kurdistan Workers Party (PKK).

Work began on Monday on unsealing the wells, and bones, plus the underwear of a man, have been found.

The bone samples have now been taken away for analysis at a laboratory. Nurisevan Elci, the prosecutor in the regional capital Sirnak Silopi who ordered the search at three separate sites, said "we do not know whether the bones are human or animal."

The area has seen scores of politically-motivated killings and disappearances in the long-running clash between the Turkish state and Kurdish separatists.

The existence of a secret unit within the Turkish forces has never been officially acknowledged. The media in Ankara has linked it to the ultra-secret secular nationalist Ergenekon group, which has faced numerous arrests and police raids for allegedly plotting against the mildly-Islamist conservative government of Prime Minister Recep Tayyip. (dpa)