In Istanbul, Turkey's biggest city, demonstrators in a group of about 250 pelted police with molotov cocktails and stones in the Gaziosmanpasa district, Anatolia news agency said.

Riot police in armored vehicles used tear gas to break up the rally and arrested five people.

In the southern city of Antalya Ocalan supporters also clashed with the police and two people were arrested.

In Izmir on the western coast, which has a substantial Kurdish minority, another demonstration went off peacefully, Anatolia said.

The 57-year-old rebel leader was condemned to death in 1999 for a separatist campaign his outlawed Kurdistan Workers' Party (PKK) has waged in predominantly Kurdish southeastern Turkey.

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

The PKK and its sympathizers have often denounced Ocalan's isolation and staged violent protests calling for his removal from solitary confinement on an island in northwest Turkey.

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.