Thousands of anti-corporate greed demonstrators have closed one of America's busiest ports.
A spokesperson for the Port of Oakland in California said maritime operations had effectively halted.
The shutdown capped a day in which hundreds of teachers and other city workers joined the call for a strike.
The crowds also stopped traffic at a junction where a military veteran was seriously injured last week as protesters clashed with police.
Ex-Marine Scott Olsen, 24, is recovering in an Oakland hospital after being struck on the head with a tear gas canister fired by police.
That incident catapulted Oakland, near San Francisco, to the centre of the national Occupy Wall Street movement and has spurred fresh demonstrations across the US.
Organisers of the latest Occupy Oakland protest said they wanted to disrupt operations at the nation's fifth busiest port, which handles about $US 39 billion a year in imports and exports, the BBC reports.
"At this time, maritime operations are effectively shut down at the Port of Oakland," the port said in a written statement.
"Maritime area operations will resume when it is safe and secure to do so."
The BBC reports Oakland has a higher than average unemployment rate and suffered badly during the US recession.
A number of businesses were shut during the Oakland demonstrations, which were attended by students, families with young children and some union activists.
Elsewhere in the US on Thursday:
- Police in Philadelphia arrested nine protesters who staged a sit-in inside the lobby of Comcast, America's largest cable firm
- In New York, about 100 military veterans marched in uniform and stopped in front of the city's stock exchange where there was a heavy police presence
- In Boston, college students and union workers marched on Bank of America offices and the statehouse to protest over the student debt crisis