May Day marches in Berlin erupted in violence as the German capital suffered its worst street clashes for four years. Injuries were reported on both sides as hundreds of protestors attacked police with stones and bottles in the central Kreuzberg district.Germany had been bracing itself for trouble with anger running high because of rising unemployment in the worst recession since World War Two. May Day is traditionally marked by mass rallies across much of the world, but the downturn in Europe’s biggest economy attracted significantly larger numbers of protestors this year. Police tried new low-profile ‘de-escalation’ tactics, to keep tension to a minimum, but moved in as darkness fell and they came under attack from stones and bottles. Similar clashes were reported in Hamburg, Dortmund and the southern city of Ulm.