Six arrested in anti-police march in Oakland, California SAN FRANCISCO (Reuters) - Six people were arrested, one for carrying a quarter-stick of dynamite, during a late-night protest march through downtown Oakland, California, marked by various acts of vandalism, police said on Sunday. The unrest Saturday night followed Twitter messages calling for an anti-police rally by individuals identifying themselves as supporters of Occupy Oakland, a local offshoot of the Occupy Wall Street demonstrations against economic inequality. Organizers said the march was aimed at protesting what they called excessive force by the Oakland Police Department. The Twitter posts urged demonstrators to dress in black and to assemble at 8 p.m. local time at Frank Ogawa Plaza, the public square taken over by Occupy Oakland activists last fall before they were evicted in a series of clashes with police. A former U.S. Marine taking part in those protests was gravely injured when he was struck in the head by a tear gas canister fired by police on October 25 during a confrontation that became a rallying cry for the anti-Wall Street movement nationwide. A second Iraq war veteran was hospitalized for severe injuries sustained in a beating by police who arrested him in another round of clashes with protesters days later. During Saturday night's disturbances, protesters lit a fire at a downtown intersection, threw bottles at police, smashed windows of police patrol cars and vandalized a media van, Oakland Police Officer Johnna Watson said in a statement. Six individuals were arrested on suspicion of such offenses as assaulting an officer, resisting arrest and vandalism. One was arrested on a charge of possession of an explosive device after being found carrying a quarter-stick of dynamite, the statement said. Police did not give a crowd estimate for Saturday's protest, but the San Francisco Chronicle reported that the rally drew a few dozen demonstrators. Police said the march was dispersed before midnight. Editing by Steve Gorman and Colleen Jenkins