PORTLAND, Ore. - Portland police removed homeless protesters who have been sitting in front of Portland's City Hall building Thursday morning. One man was arrested for not getting out of the street.

The sweep of protesters began about 6:30 a.m. after police issued a warning earlier saying the protesters were in violation of a no-camping city ordinance. A large group of officers were on hand for the confrontation, but only one person was arrested.

The protesters, most of them homeless, are upset about the ordinance and other city laws they say violate their civil rights.

Many had been camped out in front of the City Hall building for up to three weeks.

On Wednesday, Portland mayor Tom Potter warned protesters they were in violation of the law and that officers would break up the group, but the deadline for such action was flexible.

Some of the protesters left the area while others congregated across the street. City crews arrived with power-washing equipment shortly after the protesters left the sidewalk area.

Following cleanup of the area, it will be technically legal for the protesters to take their spots on the sidewalk again, which may lead police to clear them again according to current city statutes.