May be 500.000 people followed calls from leftist, communist, anarchist groups, student collectives, the relatives of the Tempi victims, the calls for general strike from unions, the calls from organized football hooligans, to join a gathering at Syntagma Square in the center of Athens. see one of the many calls https://athens.indymedia.org/post/1634333/ Biggest gathering since long time. The crowd took over the surrounding avenues from 9 o clock in the morning until early evening. Also participating, voters of ND government, nationalists and few nazis, which got beaten up in between.
