Nasty gang related I would suspect.
Asian gangs are really nasty I understand.
When I lived in the ROC, the police would send out two heavily armed platoons that would hit various gang establishments. It was wild to watch. One time I was in club that quickly cleared out (I unfortunately didn't notice this). The next thing a gang member stood on top of a table and yelled something. The gang destroyed the place around me. Glass was flying everywhere.