A confrontation between rival bikie gangs saw 12 members ejected from the Danny Green fight in Perth. West Australian Police Commissioner Karl O'Callaghan confirmed on Thursday two gang members were arrested, with one charged with assaulting a public officer. They were led out of Challenge Stadium by members of the Gang Crime Squad during the cruiserweight bout between Green and Poland's Krzysztof Wlodarczyk on Wednesday night. It is believed the initial confrontation was between members of the outlaw Gypsy Jokers and Comancheros motorcycle gangs. "It's not an unusual occurrence at these sorts of events - it is one reason why we have such a large security response," Mr O'Callaghan said.