| OAKLAND, Calif
OAKLAND, Calif Scores of protesters were arrested and eight people injured on Thursday in Oakland clashes that activists and officials blamed on agitators who provoked police after a day of mostly peaceful rallies against economic inequality.
Busloads of police in riot gear advanced on demonstrators overnight firing tear gas to disperse hundreds lingering in downtown streets hours after protesters numbering in the thousands had forced a shutdown of the busy Port of Oakland.
The clampdown appeared aimed at preventing protesters from expanding their foothold in the streets around a public plaza that has become a hub for demonstrations in Oakland, a largely working-class city on the eastern banks of San Francisco Bay.
Police from about 15 agencies arrested more than 80 people, and five civilians and three officers were injured in the melee, the city said. There was no immediate word on the nature or severity of those injuries.
City officials said police acted in response to "a select group of people intent on engaging in illegal activity -- including vandalizing property, lighting fires and assaulting the police."
Their statement said some protesters also broke into and seized control of a downtown building, which demonstrators said was vacant, and set several fires.
"We had the opportunity to isolate the main group of people who seemed to be hiding in the crowd all day," Mayor Jean Quan told a news conference. "The police, I think, very effectively got in and surrounded and arrested them."
Many activists from the Occupy Oakland movement -- aligned with anti-Wall Street protests in New York and elsewhere against corporate excesses, high unemployment and bank bailouts -- also blamed individuals they said gave police a pretext for heavy-handed tactics by engaging in vandalism and unruliness.
"Everything went beautiful until these guys (came) with scarves around their mouths, and then all hell broke loose. Our city just got demolished," said Johnny Allen, 60, a health-care provider sweeping debris from in front of City Hall.
Protesters who claimed responsibility for taking over the downtown building, which had once housed a nonprofit agency for the homeless, said in a statement their action was illegal, but said "the ferocity of the police response surprised us."
Acting Police Chief Howard Jordan said those protesters were known to possess "incendiary devices" and had lit "garbage cans and other things on fire" when police moved in. "There was a concern that they would start a fire inside the building."
The unrest in Oakland, which shot to the forefront of nationwide Occupy Wall Street protests, came a week after a former Marine, Scott Olsen, was badly injured in previous clashes between police and protesters.
It was the wounding of Olsen, an Iraq war veteran turned peace activist, that seemed to galvanize Oakland's demonstrators and helped broaden their grievances to include police brutality.
Following a day of citywide rallies that drew some 7,000 activists at their height, authorities early Thursday sought to pen demonstrators back inside Frank Ogawa Plaza, a public square next to City Hall that protesters have used as a camp since last month.
Despite some early vandalism, however, demonstrators on the scene had said downtown streets were largely calm when police who had stayed at a distance throughout the day arrived at about midnight and ordered the crowd to disperse its "unlawful assembly."
Lined up shoulder to shoulder, police fired volleys of tear gas, forcing the demonstrators to retreat to the plaza, then made a second charge with batons and tear gas about an hour later to drive protesters farther into the square's interior.
Some protesters hurled tear gas canisters and rocks back at police as they fled. At least one protester was seen being carried away with an injury to his leg. Another who had been arrested, his hands bound behind him, lay on the ground with blood streaming down his face.
One arrested protester, Adam Konner, 29, of Ann Arbor, Michigan, said he didn't clearly hear a police announcement ordering "campers to move back to your tents," before officers rushed in.
"I was trying to figure what they were saying. I was trying to figure out if I could go back into the plaza," he told Reuters, recounting that he was knocked to the ground and restrained.
Evidence of unrest was visible at daylight.
City crews pressure-washed graffiti declaring "kill cops" and "smash" from private and municipal buildings around the plaza, still filled with dozens of tents.
The Port of Oakland, the nation's fourth busiest maritime container-cargo hub with $39 billion in yearly imports and exports, was back in full swing by late morning after it was shut down by the protests on Wednesday.
Occupy movement protesters sought to distance themselves from "anarchist" agitators among them, and disagreements had flared overnight between a minority who set up trash-can barricades and others, often older demonstrators, who lectured about the need to keep protests peaceful.
A sign on a coffee shop with a shattered window offered an apology: "We're sorry. This does not represent us."
"It makes me mad, but I'm still going to fight for my rights. I'm not going anywhere," Perry Dera, a 31-year-old Oakland resident and protester, said.
(Reporting by Noel Randewich, Dan Levine, Lisa Baertlein, Peter Henderson and Jim Christie; Writing by Steve Gorman; Editing by Cynthia Johnston)