Supporters of the Occupy Wall Street movement are condemning the violence and vandalism that broke out during a protest through Oakland, California.

Demonstrators blame the violence on outsiders who they say showed up just to cause trouble. Organizers of the Oakland march were meeting Thursday on a formal statement disavowing their movement from the violence.

Police used tear gas when a number of protesters temporarily shut down the Port of Oakland, one of the country's busiest seaports. Marchers blocked gates and tried to take over an empty building.

Oakland city officials also say marchers broke windows, splashed pain on storefronts, and set fires in the downtown business district.

Police arrested dozens of people and several protesters were hurt.

Demonstrators aligned with the Occupy Wall Street movement have sprung up in public parks and squares in major cities across the United States. Protesters have numerous demands, including ending U.S. foreign military action, raising taxes on the wealthy, and more government social spending.