(Portland, OR)  --  Police are saying they arrested three people after protests turned violent at Portland's Waterfront.  Several members of the opposing groups "Antifa" and the right-wing "Patriot Prayer" group clashed yesterday at the "Patriot Prayer" group's "Freedom March" at the Salmon Street Springs Fountain.  Officials say members of the peaceful Rally for Freedom, Solidarity and Justice at the Oregon Memorial Marine Park near the Waterfront moved across the street to avoid the violence.