Clashes at Occupy Oakland protest

Tension in an Occupy Oakland protest.
Police fired tear gas at hundreds of protesters who were trying to take control of a building in downtown Oakland.
Nineteen people were arrested, and three officers were injured.
Police said the clashes erupted when protesters began destroying construction equipment and tearing down the fences of the Henry J. Kaiser Convention Center.
They had vowed to occupy the center to establish a new headquarters.
Police declared an unlawful assembly and told them to disperse.
Oakland Police said officers were pelted with bottles, metal pipes, rocks and improvised explosive devices.
They returned to a plaza after being dispersed, and threatened to march to another abandoned building.
The scuffles are not the first between Occupy Oakland activists and police.
The Occupy Wall Street movement, which originated in New York, is trying to regain lost momentum after protest camps around the country were cleared late last year.
Michaela Cabrera, Reuters.