Police have made more than 50 arrests, with more arrests expected as officers try to maintain the peace in downtown Oakland.
Oakland Police Chief Anthony Batts said that officers are "focused on arrests at this point in time." He expected the number of arrests to double during the night.
Several business were damaged, including a Foot Locker store that was looted and a jewelry store that was ransacked. Windows were also smashed at several other businesses.
Batts says officers from 15 different agencies responded to help Oakland police.
Firefighters were also called out to put out fires in several trash bins and at least one dumpster.
Batts said earlier one person suffered a leg injury when some protesters started throwing rocks and bottles.