I am from Poland. It is Eastern-Central Europa. I confirm this what Ted Mark wrote. Gang in my city Płock is also . They are the fanatics of Wisła Płock's soccer team. Boys and girls belong to gang . They do not fight already on stadia's because they fear police and courts after introduction of heavy penalties . Boys or/and girls make an appointment to fight with different gangs. Very often fights in secluded spot. In forest or on meadow outside the town. This is hereinafter to nobody would notified police. Different gangs are the fanatics of different soccer teams.