Deputies and mayors of the DTP party have said they will be fasting until late Monday in a tent set up in a park of Diyarbakir, the main city of Turkey's southeastern Anatolia region whose population is predominantly Kurdish.

DTP chief Ahmet Turk said dozens of people had been arrested over the past weeks, including many DTP members, for their alleged collusion with the rebel Kurdistan Workers' Party (PKK).

The arrests would not encourage PKK rebels to come down from the mountains to give themselves up and might even encourage some people to join them, he said.

Turkish army chief Ilker Basbug last month called on the government to change the law to make it easier for the rebels to give up.

The PKK, which Ankara and much of the international community lists as a terrorist organisation, took up arms for self-rule in Turkey's mainly Kurdish southeast in 1984, sparking a conflict that has claimed 45,000 lives.

Ankara says about 2,000 PKK rebels are holed up in the mountains of northern Iraq, from where they launch attacks on Turkish territory.

The DTP has 21 of the 550 seats in the Turkish parliament.

But the party could be banned by the constitutional court, which is currently investigationg allegations that it is cooperating with the PKK.