OAKLAND, Calif. (AP) -- Police have used tear gas and flash bang grenades on demonstrators in Oakland, Calif., as authorities say a protest involving an estimated 2,000 people turned violent.
Officer Jeff Thomason says about 10 people were arrested Saturday afternoon when some in the crowd started throwing objects at police.
Oakland officials say about 250 people were in the group when the protest started on the city's streets around noon Saturday, with demonstrators threatening to take over a vacant building. But KCBS-AM reports the crowd has since grown to about 2,000.
The group was being monitored by dozens of Oakland police officers, as well as officers from nearby police agencies. Police began firing tear gas and flash bang grenades as things began to get out of hand.
The protest comes after Occupy protesters said earlier this week that they planned to move into a vacant building and turn it into a social center and political hub.