The agency said the professor was named as Busra Ersanli and the publisher as Ragip Zarakolu of Belge Publishing. Ersanli is also a member of the pro-Kurdish Peace and Democracy Party, private NTV television said.

The court, which was investigating the urban wing of the outlawed Kurdistan Workers' Party (PKK), released three suspects, Anatolia said.

Currently, more than 2,500 Kurds, including and five lawmakers and other members of the Peace and Democracy Party, are in jail on the same charge.

The PKK, listed as a terrorist group by Ankara and much of the international community, took up arms in Kurdish-majority southeast Turkey in 1984, sparking a conflict that has claimed about 45,000 lives.