On Saturday night - three days after Mayor Ted Wheeler called protesters 'attempted murderers' after protesters tried to burn down a police precinct while officers were still inside - another group of protesters broke into a police union building and set a 'mostly peaceful' fire.

Three officers were injured including one who was hospitalized, as police attempted to clear several hundred protesters from the Portland Police Association (PPA) building, according to a statement reported by the Daily Mail.

Police said a group from Peninsula Park marched to the PPA building, which is located about five miles north of the federal courthouse that had been the target of nightly violence earlier this summer.  

About 20 demonstrators reportedly broke into the building, set the fire and were adding to it when officers made the riot declaration just after 11.30pm. 

Video showed smoke and flames in the building as officers outside formed a line and used flash bangs and smoke canisters to force the protest several blocks away. -Daily Mail