In the period after the fall of the Berlin Wall, the German black bloc movement continued traditional riots such as May Day in Berlin-Kreuzberg, but with decreasing intensity. Their main focus became the struggle against the recurring popularity of Neo-Nazism in Germany. The "turn" came in June 2007, during the 33rd G8 summit. A black bloc of 2,000 people built barricades, set cars alight and attacked the police during a mass demonstration in Rostock. 400 police officers were injured, as well as about 500 demonstrators and activists. According to the German Verfassungsschutz, the weeks of organisation before the demonstration and the riots themselves amounted to a revival for the militant left in Germany. Since the "Battle of Rostock", traditional "May Day Riots" after demonstrations every 1 May in Berlin, and since 2008 also in Hamburg, became more intense.