German police said Wednesday they briefly detained seven demonstrators in Frankfurt after an overnight protest in sympathy with Greece's anarchist movement turned violent, reported dpa.
About 100 demonstrators rallied outside the Greek consulate in the German city late Tuesday, before fanning out in smaller groups through the inner city.
Some went on to smash the plate-glass window of a bank, strew garbage from nearby bins and overturn a building-site fence, police said.
German anarchists have also demonstrated this week in Berlin and Dresden against the Greek authorities.