Greek farmers protesting planned tax hikes and pension changes have left a central Athens square where they had been camped out since Friday but are vowing to keep protesting until the government listens.

The farmers, who had set up 68 blockades with tractors and agricultural vehicles on highways across Greece, will convene Monday to decide how to proceed, farmers' representative Vangelis Boutas said. He said they also want measures to lower production costs, such as tax-free diesel, cheaper electricity and no VAT on supplies.

Earlier Saturday, police estimated that 12,000 protesters marched to Athens' Syntagma Square outside Parliament to support the farmers. The march was called by unions allied with Greece's Communist Party.

Police also arrested a 30-year-old for attacking a patrol car during Friday's clashes between farmers and police.