(Portland, OR) -- The Portland Police Bureau says officers responded to multiple demonstrations in downtown Portland on July 4th. Opposing groups had physical confrontations. Police had the Rapid Response Team, Dialogue Officers, a public address vehicle and the Air Support Unit monitor the event. Officers had a visible presence on the street, which they think helped reduce criminal activity. One man was arrested for using a stick to damage a utility box and another man was arrested for adding accelerant to a fire. No significant injuries were reported.