(Portland, OR) -- Protesters are pledging to engage in "unrest" tomorrow unless the Portland Police Bureau's chief is fired. Demonstrators say people were hurt Friday during the Inauguration Day protest when officers used flashbang grenades and pepper spray against marchers who were attempting to enter local bridges. Police say they were responding to protesters who threw "rocks, bottles, flares and unknown liquids" at officers in riot gear. Some protesters say it was police who incited the violence, and "unrest" will result tomorrow unless Police Chief Michael Marshman is fired. Mayor Ted Wheeler tells KOIN-TV police acted properly during the demonstration.