
The demonstrators had attempted to take over vacant buildings to use as their headquarters, they also broke into City Hall and tried to occupy a YMCA. Police spokesman Jeff Thomason told media most of the arrests came around 8 pm local time. Police took many protesters into custody as they marched through the city's downtown area, with some entering a YMCA building.
Officials say, at one point protesters began tearing down perimeter fences around the Henry J. Kaiser Convention Center, as some attacked police officers, throwing rocks, bottles and other objects. Police declared an unlawful assembly and used force, according to the Oakland Tribune newspaper.
While police were taking people into custody near the YMCA, about 100 officers surrounded City Hall, while others swept the inside of the building for protesters who had broken in. Inside the building, protesters burned flags, broke into an electrical box and damaged several art structures, according to Oakland Mayor Jean Quan.