(Portland, OR)  --  Police say they've made several arrests after social justice protests allegedly turned violent in North Portland overnight.  Police say crowds set fires, vandalized the Portland Police Bureau's North Precinct and looted a business early this morning.  Police declared an unlawful assembly outside the North Precinct after protesters allegedly created barricades on the streets surrounding the building.  Police used flash-bangs to disperse the crowd shortly before 4 a.m.