Police have arrested scores of protesters, including 12 foreigners, after breaking up riots in Greece's second largest city in which shops were smashed and buildings set ablaze, including a McDonald's.
A group of 200 self-styled anarchists were among 25,000 mainly peaceful anti-capitalist protesters who marched in late afternoon on Saturday through Thessaloniki's centre, about 80 km (50 miles) west of where a European Union summit ended earlier in the day.
"They threw petrol bombs into the McDonald's and planted anarchist black flags on the footpath outside," Reuters correspondent Philip Pangalos said. "Others attacked nearby shops with axes and sticks."
Demonstrators also torched a Vodafone store, witnesses said.
About 30 shops as well as three branches of Greek banks were badly damaged with windows smashed and petrol bombs thrown inside.
Riot police used baton charges and teargas to drive the attackers away from an area about half a kilometre from the U.S. consulate.
About a dozen shop and building entrances as well as five cars were still ablaze two hours after the violence erupted. Thick smoke and clouds of teargas billowed from the city centre.