"To me the resistance movement makes a lot of sense and I salute it," Ocalan said in a message.

His words were read out by an official from Turkey's main pro-Kurdish political party, the BNP following a visit to the Imrali island prison where the Kurdish rebel chief is serving a life sentence.

Ocalan warned the protesters, who are calling for Prime Minister Recep Tayyip Erdogan to go, not to let their movement be overtaken by Turkish nationalists, CNN-Turk reported on its website.

Erdogan said Friday his Islamic-rooted government was open to "democratic demands" as he hit back at EU criticism of his handling of a week of deadly unrest.

Turkey's trouble began when police cracked down heavily on a peaceful campaign to save Istanbul's Gezi Park, spiralling into nationwide demonstrations against Erdogan and his Justice and Development Party (AKP), seen as increasingly authoritarian by the protesters.

Last week Kurdish rebels shot at a Turkish army base on the country's border with Iraq, prompting soldiers to return fire, in the first reported hostilities since a March ceasefire.

The PKK rebels have been leaving Turkey in groups under a peace deal Ankara reached with their leader Ocalan who is serving his life sentence in an isolated island prison in the Marmara Sea south of Istanbul following his capture in Nairobi in 1999.

Ocalan called on March 21 for his fighters to lay down their arms and withdraw from Turkish soil in a breakthrough announcement after months of clandestine negotiations with the Turkish secret service aimed at ending the Kurdish rebellion.

The PKK's armed campaign for self-rule has killed some 45,000 people, mostly Kurds, since 1984 and the group is considered a terrorist organisation by Ankara and its Western allies.