Police have been accused of firing rubber bullets and tear gas at people protesting gold mining in Skouries, Halkidiki, on Sunday.
Groups of protesters gathered in the village of Ierissos and marched towards the woods in Skouries, where the felling of trees had begun. But they were turned back by riot police.
Protesters have published photos on the Internet showing tear gas canisters used by the police and what appear to be injuries from rubber bullets.
Police said three patrol cars caught fire during the clashes. Calm was restored at about 6 p.m. but a heavy police presence remained in the area.
Last month, the Council of State issued a decision allowing gold mining in Skouries to continue for the time being despite complaints by locals about the potential environmental damage it could cause.
Nine residents associations, cooperatives and professional groups from the villages of Ierissos and Megali Panaghia and other parts of Cassandra appealed against a joint-ministerial decision in July 2011, which allowed Hellenic Gold, a subsidiary of Canadian firm Eldorado Gold, to dig in Skouries.
They argued that it would lead to the destruction of a local forest and irreversible damage to the ecosystem.
The company has been awarded an area of 26,400 hectares, of which 410 is forest land. Almost all the trees in the forest will be cut down as part of the mining firm?s plan to extract gold. The company says it will replant trees when it finishes its work.
The court decided to throw out the residents? appeal because the ?investment is very beneficial for the economy.? Judges argued that the mine would employ up to 1,300 people in an area with high unemployment and would help the struggling national economy.
?We are determined to continue the struggle to ensure that the land will not be sold of and the interests of the Canadian company,? local SYRIZA MP Katerina Igglezi told Athens-Macedonia News Agency on Sunday.