At least one protester has been injured as riot police were clearing an OWS encampment in a downtown Portland park area in Oregon, USA, on Saturday night. The teenager was hit in the face with a police baton. Several others were arrested.

­Police say officers began detaining demonstrators at South Park blocks around 8:30pm after the park was closed 30 minutes early, AP reports.Protesters are posting photographic evidence of police brutality during their raids. One of them shows 15-year-old Walker Prettyman, who was injured during the Occupy Portland protest in Shemanski Park. According to the young man, a police officer hit him in the face with his baton.(Ray Whitehouse/The Oregonian) Eventually, despite the ban from the city officials put on overnight camping, Occupy Portland demonstrators set up their tents in the park in south-western Portland.After Portland police arrested those protesters who refused to leave encampments Saturday night, OWS demonstrators moved towards City Hall and continued their protests without attempting to “occupy” any place, while riot police gathered in groups near the building.According to the latest updates, hundreds of protesters returned to the South Park blocks, partying. No further action from the authorities has followed so far, but police say they are ready to perform new arrests."We'll arrest people if we have to. We'll deal with it as we need to," OregonLive.com quoted a spokesman for the Portland Police Bureau, Sgt. Pete Simpson, as saying."We'll encourage people to leave and not be arrested," he added.There have been no camps set up in Portland in the past three weeks, since last police raid in the city center. The same as this time, authorities were dismantling the tents and arresting protesters.At a Friday morning news conference, Occupy spokesman Jordan Ledoux said that having a central place for the movement is essential to receive cash and food donations, OregonLive.com quoted him.In response to the group's message, Portland’s mayor Sam Adams said "we simply cannot afford another encampment in our city. I would much rather spend our finite dollars on direct services to those in need, rather than patrolling and cleaning up after an encampment," the website quoted him as saying.