Aydin Budak, mayor of the town of Cizre and member of the Democratic Society Party (DTP), the main Kurdish political movement in Turkey, was remanded in custody pending trial for a speech he made on March 21 during Newroz, the Kurdish new year.

DTP members have increasingly become the target of judicial action in recent weeks on charges of supporting the Kurdistan Workers' Party (PKK), which has waged a bloody campaign for Kurdish self-rule in the southeast since 1984.

The PKK is listed as a terrorist group by Ankara and much of the international community.

Budak was charged with praising an illegal organisation and making its propaganda, and of inciting hatred among the population, the sources said.

Prosecutors now have to draw up a detailed indictment for the trial to start.

In his Newroz speech, Budak sent greetings to PKK leader Abdullah Ocalan, who has been serving a life sentence for separatism since 1999, and insisted that millions of Kurds see him as their leader.

Prosecutors have also launched a preliminary investigation against Prime Minister Recep Tayyip Erdogan on charges that he praised Ocalan by calling him "sayin" -- a word meaning esteemed or honorable, but which also doubles for "mister" -- in a radio interview in 2000.

The Kurdish conflict in Turkey has claimed more than 37,000 lives since the PKK took up arms in 1984.