I watched it in indonesia, the gang fights over there were massive like young and dangerous style. Of course spears aren't the only weapon they have, they also throw rocks and bring machetes. Basically they fight long range with rocks as main weapons, spears were used to keep the opponets away and machetes for close combat. They don't need to conceal anything, each gangs have their own territory, with gov tacit blessing, they disguised themselves as legitimate organizations and even collected protection fee using receipt, LOL. Of course when they fight, the police will come, few will be arrested, then life goes back to normal like nothing ever happen.