About 100 demonstrators, shouting slogans in support of the jailed leader of the rebel Kurdistan Workers Party (PKK), threw stones at an equivalent number of riot police who had come to disperse the protest.

The police fired tear gas grenades and plastic bullets against the protesters, but no one was hurt in the melee in Dolapdere, located in Istanbul's western side.

On the eastern bank of the Bosphorus Strait, in Umraniye district, pro-PKK demonstrators torched a city bus with a petrol bomb, slightly injuring its driver, the Anatolia news agency reported.

Ocalan was sentenced to death in 1999 for his role in his group's bloody armed campaign for self-rule in Turkey's mainly Kurdish-populated southeast.

His sentence was commuted to life in prison in 2002 after Turkey abolished capital punishment as part of reforms to boost its bid to join the European Union.

Last year, Ankara introduced restrictions on Ocalan's meetings with his lawyers, whom it accused of carrying orders from the rebel leader to his militants who have recently stepped up their armed campaign.

The Kurdish conflict in Turkey has claimed some 37,000 lives since 1984 when the PKK took up arms for self-rule in the predominantly Kurdish southeast.