Demonstrators marched through holiday traffic, blocked intersections and shut down light rail service to Westlake station. Some protesters moved the demonstration to the edge of the Capitol Hill neighborhood, where they clashed with police officers. Both officers and demonstrators used pepper spray, police said. Some protesters wore gas masks. Later, the city's traditional Christmas lighting ceremony at Westlake started early after protesters surrounded the area and began rallying. Police turned out in force, arresting five people and prompting the mall to close several hours early.