Photos: At Occupy Oakland, a Night of Protests and Tear Gas

Police in riot gear fired tear gas into the crowd at least five times in an effort to clear the plaza in front of Oakland City Hall.

The epicenter of the protest movement against economic injustice shifted west on Tuesday, with police and demonstrators clashing at Occupy Oakland. The confrontation began in the wee hours of the morning, when police swept in to evict protesters from the camp they'd occupied for two weeks on the plaza outside Oakland City Hall. Last night, several hundred activists regrouped for a march to retake what many of them call Oscar Grant Plaza—a reference to an unarmed man killed by local transit police in 2009.

Over the course of the evening, police in riot gear fired tear gas and pepper balls into the crowd at least five times, sending people running for cover. More than 100 demonstrators were arrested, and Occupy Oakland organizers pledged another protest for Wednesday night to continue the effort to move back onto the plaza.