OAKLAND -- A majority of Occupy Oakland protesters sought Thursday to distance themselves from masked vandals who they said had undercut the movement by hijacking the tail end of a mostly peaceful protest, damaging downtown buildings and clashing with police.

"They are smearing our movement," Raleigh Latham, a filmmaker who has covered the Occupy protests, said to applause at a morning meeting of about 60 people at the movement's City Hall camp. "People who want to destroy our community are not welcome here."

They may not be welcomed by all of Occupy's committed sympathizers. But the hundreds of black-clad activists who coalesced downtown late Wednesday to take over a vacant building, barricade a street and then battle with police and vandalize stores are proving to be a complicated problem for the leaderless movement.

Many protesters, while saying they favor nonviolence, believe in provocative actions like marching on businesses and forcefully shutting them down - which happened at several bank branches during the comparatively peaceful daytime hours of Wednesday's general strike.

Still other protesters said Thursday that they saw value in chaos, or believed vandalism was an inevitable expression of rage by disenfranchised young people.

"These are drastic measures," said a masked 24-year-old from Oakland, "to make people listen."

Internal dissent

An afternoon press conference called by Occupy demonstrators at their encampment in Frank Ogawa Plaza devolved into a shouting match over questions about tactics. Some dismissed the late-night vandalism as a trivial side issue, dwarfed by the ability of thousands of protesters hours earlier to shut down the port without incident.

"I think it's extremely irrelevant," said Verucha Peller. "I think the people of Oakland were highly reassured by the unity of this community."

But Michael Turner said such action was meaningful. "A few broken windows is a reflection of what I feel. I can understand why people would have the rage to go and break something. The general consensus is that this is peaceful, but there's no guarantee it will be peaceful."

Few in the Occupy camp spoke in favor of the contingent of violent protesters, who use what are often referred to as "black bloc" tactics and have been a source of debate in the Bay Area activist community for years.

It's not clear, though, how those advocating for peaceful protest can stop agitators from exploiting their energy. Rachel Dorney, a 23-year-old math tutor, suggested that people can do more to confront the vandals, saying, "Maybe we have to take the brick out of their hand."

Several activists attempted to do just that on Wednesday, both when banks and a Whole Foods store were vandalized during the day and when the unrest started up late at night. They met with some success, but the smashed windows and widespread graffiti showed it was far from complete.

Dorney proposed that Occupy Oakland pass a resolution apologizing or expressing regret to local businesses for the overnight destruction. But others balked, saying they weren't responsible for rogue vandals. The group instead agreed that it should offer to assist nearby businesses.

The street clashes early Thursday injured five protesters and three police officers and led to 103 arrests, including charges of assaulting a police officer and felony vandalism, according to interim Police Chief Howard Jordan.

Seizing empty building

The trouble began before 11 p.m., when dozens of protesters took over a vacant two-story building at 16th Street and Broadway that once housed the nonprofit Travelers Aid Society.

Hundreds of others looked on as protesters barricaded 16th Street at both ends with wooden pallets, trash cans, tables and tires. One group of protesters broke cement blocks into baseball-size chunks.

Police had kept their distance from Occupy Oakland protesters since coming under scrutiny for deploying tear gas and flash-bang grenades and firing projectiles in a clash last week that left one demonstrator with a serious head injury. Critics said officers had used excessive force and violated city policies on crowd control.

Just before midnight, however, hundreds of officers from several agencies responded to the area. Jordan said they had closed in because they feared protesters might burn down the vacant building.

Police found protesters - many covering their faces with bandanas and some in gas masks - feeding a massive trash fire at 16th and Broadway that sent flames 15 feet high.

Just after midnight, police ordered the crowd to disperse. Soon, one officer on Broadway was struck on his face shield by a bottle. Within a minute, officers launched flash-bang grenades and tear-gas canisters. Protesters scattered and a fire crew put out the blaze.

The crowd quickly regrouped and entered into a standoff with officers on Broadway. Another confrontation happened at 16th Street and San Pablo Avenue, where police corralled protesters, read dispersal orders and made the mass arrests.

Police said protesters had thrown pipes, hammers, bottles, rocks and cobblestones. On Thursday, they displayed some of the items they said were seized - shields, sticks, spray-paint tanks, bottles and rocks.

Street debate

Many protesters said police had escalated the situation and should not have used tear gas. But they were also deeply split over what happened. Some scolded window-breakers and told them Occupy Oakland was supposed to be a peaceful protest.

"Violence is not a statement," one protester shouted after a man in a mask broke a clothing store window.

As protesters built one of the barricades on 16th Street, a nearby resident who had joined Wednesday's general strike walked up and began to take it apart. But whenever he moved a trash can or table or pallet, a man in a mask would put it back.

"What does putting trash in the street accomplish?" asked the neighbor, 35-year-old Tarrell Gamble, as a crowd confronted him. "This is somebody's property."

Masked men shouted and swore at Gamble, and one protester briefly put him in a headlock.

After two women escorted him away, Gamble said, "The protest is supposed to be about corporate greed. It's not about trashing the streets of Oakland."