Article published on the 2008-10-19 Latest update 2008-10-19 11:08 TU
In Diyarbakir, the largest city in mainly-Kurdish south-eastern Turkey, 5,000 people protested. Police fired tear gas and used water-cannon after being stoned by demonstrators, according to the Anatolia news agency.
Several thousand demonstrated in the small town of Yuksekova, near the border with Iraq and Iran, with police dispersing the crowd after roadblocks were set up and tyres burned.
A car bomb injured one protester.
Police say that they have made dozens of arrests in both towns.
On Friday there were clashes in the capital, Istanbul, with petrol bombs damaging a shopping centre.
The pro-Kurd news agency Firat says that police broke up protests in at least four other towns, with vehicles being set on fire in Sanliurfa, in the south-east.
Turkish nationalists staged counter-demonstrations on Saturday, rejecting calls of self-determination for Kurds under the slogan "one nation, one flag".
Lawyers representing Ocalan, who was captured in Kenya in 1999 and jailed for life for leading the PKK guerrilla movement, say that he has been assaulted by a prison guard and threatened with death in his island prison of Irmali, where he is held in solitary confinement.