Article published on the 2008-12-12 Latest update 2008-12-12 14:20 TU
A small group of masked youth separated from the mass demonstration and began attacking police. Riot police then charged the group of about 100, and wrestled many of them to the ground, eye witnesses said.
Television images showed groups of masked youth charging through downtown Athens, smashing festive decorations and overturning Christmas trees.
Two more demonstrations were scheduled in the eastern port city of Thessaloniki on Friday afternoon.
Elsewhere in the capital, an unrelated demonstration of football fans turned violent outside of a courthouse where 27 football supporters were being tried for the murder of a supporter of a rival team.
Greek Prime Minister Costas Karamanlis, who has already weathered several corruption scandals, is to fly back from the EU summit in Brussels Friday in the face of calls from the opposition to resign.
Protests and fighing in Greece