The 300-strong group gathered in the small town of Cizre, close to the border with Syria, chanting slogans in favour of Ocalan and refusing police orders to disperse, local security sources said.

Police moved in on the group when the protestors pelted officers with stones and attacked them with wooden sticks, they added.

Ocalan, leader of the outlawed Kurdistan Workers' Party (PKK), was captured in Kenya on February 15, 1999 after he was forced to leave the Greek embassy where he had been taking refuge.

The 57-year-old rebel leader was condemned to death in 1999 for the armed separatist campaign the PKK has waged since 1984 in southeastern Turkey.

The sentence was commuted to life imprisonment in 2002 after Ankara abolished capital punishment as part of efforts to align with the norms of the European Union.

Ocalan has since been kept in solitary confinement on an island in northwestern Turkey.

Kurdish activists have long been calling for end to Ocalan's isolation and his transfer to an ordinary jail, but their appeals have so far fallen on deaf ears in Ankara.

The Kurdish conflict has claimed some 37,000 lives since 1984 when the PKK, blacklisted as a terrorist group by Turkey as well as the EU and the United States, took up arms for Kurdish self-rule in the southeast.