Oakland erupts into violence as demonstrators shut down port

The Occupy Wall Street movement demonstrated both its power and its potentially ugly side as demonstrators in the Californian city of Oakland shut down the fifth-busiest port in the US, before a night of violence that landed at least four protesters in hospital.

Anti-capitalist campaigners barricaded entrances to Oakland harbour on Wednesday night to prevent shift workers getting to their jobs.

It was supposed to be the triumphant culmination of a day of marches and action that drew 7,000 people, one of the largest events in the seven-week-old movement that began in the US financial capital, New York, and has spawned copycats across the US and around the world.

The Occupy Wall Street movement started when several hundred demonstrators pitched a tent city in Zuccotti Park, a stone's throw from Wall Street. Yesterday, dozens of activists staged a mock trial of the investment bank Goldman Sachs in the park, finding it guilty of corruption. A march on the bank's nearby headquarters, and an attempt to stage a sit-in, led to 12 arrests.

Oakland has become a focal point for the movement, not just to protest inequality but also to protect the right to peaceful protest. Last week an Iraq war veteran, Scott Olsen, was hospitalised with injuries from a police projectile during an attempt to clear the city centre of its protest camp.

The abiding images of the latest protests, though, will not be of the peaceful evening marches but of the clashes with police. Buildings had their windows smashed and makeshift barricades were set ablaze. Police said protesters pelted them with concrete blocks and Molotov cocktails. Officers arrested 12 people.

The trigger for the clashes appeared to have been demonstrators' determination to occupy an empty office building in the city centre, vacant since funding cuts forced the closure of a charity based there. A banner with the phrase "Occupy Everything" was slung over the door as people forced their way in. The crowd passed around leaflets declaring the building had been taken for "reuse", while on Twitter the office was declared to be a new community centre.

The Port of Oakland said evening operations had been "effectively shut down", but it reopened yesterday morning after protesters removed a blockade limiting access. Port spokesman Isaac Kos-Read said workers immediately began returning to their jobs and operations partially resumed.

In other cities, smaller-scale demonstrations were also held to show solidarity with Occupy Oakland and to protest the injuries to Mr Olsen.

New York, Philadelphia and Los Angeles saw small events.

Occupations around the world

Canada

The Occupy Toronto site now comprises hundreds of tents, complete with a mini-library, around 12 portable toilets and three yurts worth $20,000 (around £12,300) each. They plan to stay put through Christmas.

Australia

Police are seeking a Supreme Court order to prevent a Occupy Sydney protest planned for Saturday, because they say it would block the city's business district. Occupy Brisbane protesters continue to demonstrate despite a series of evictions from makeshift camps.

Germany

Clergy at the church of St Petri and St Marien in Berlin have welcomed around 30 protesters to camp in the churchyard. Police have prevented demonstrators from setting up tents in the Platz der Republik opposite the Reichstag parliament building.