More than 1,000 Occupy Wall Street protesters have blocked cargo trucks at some of the West Coast's busiest ports, forcing terminals in Oakland, California, Portland, Oregon, and Washington state to halt operations.

Protesters block an entrance to the Port of Longview in Longview, Wash., Monday, Dec. 12, 2011. Anti-Wall Street protesters along the West Coast joined an effort Monday to blockade some of the nation's busiest docks, with the idea that if they cut off the ports, they cut into corporate profits. (AP Photo/Don Ryan) While the protests attracted fewer people than the 10,000 who turned out on November 2 to shut down Oakland's port, organisers declared victory and promised more demonstrations to come.

"The truckers are still here, but there's nobody here to unload their stuff," protest organiser Boots Riley said. "We shut down the Port of Oakland for the daytime shift and we're coming back in the evening. Mission accomplished."

Organisers called for the "Shutdown Wall Street on the Waterfront" protests, hoping the day of demonstrations would cut into the profits of the corporations that run the docks and send a message that their movement was not over.

The longshoremen's union did not officially support the protests, but its membership cited a provision in its contract that allowed workers to ask to stay off the job if they felt conditions were unsafe.

Some went home with several hours' pay while others left with nothing.

Oakland longshoreman DeAndre Whitten, who lost about 500 dollars, said: "I hope they keep it up. I have no problem with it. But my wife wasn't happy about it."

Others, such as the truck drivers who had to wait in long lines as protesters blocked gates, were angry, saying the demonstrators were harming the people they were trying to help.

"This is a joke. What are they protesting?" said Christian Vega, who sat in his truck carrying a load of recycled paper. He said the delay was costing him 600 dollars. "It only hurts me and the other drivers. We have jobs and families to support and feed. Most of them don't."

From Long Beach, California, to as far away as Anchorage, Alaska, and Vancouver, British Columbia, protesters beat drums and carried signs as they marched outside the gates. There were a handful of arrests, but no major clashes with police.

Rain dampened some protests. Several hundred showed up at the Port of Long Beach and left after several hours.

The movement, which sprang up this autumn in New York against what it sees as corporate greed and economic inequality, is focusing on the ports as the "economic engines for the elite". It comes weeks after police raids cleared out most of their tent camps.

The port protests are a "response to show them that it's going to hurt their pocketbooks if they attack us brutally like that", Mr Riley said.

Protesters are most upset by two West Coast companies: port operator SSA Marine and grain exporter EGT. Investment banking giant Goldman Sachs Group owns a major stake in SSA Marine and has been a frequent target of protesters.

They say they are standing up for workers against the port companies, which have had high-profile clashes with union workers lately. Longshoremen in Longview, for example, have had a long-standing dispute with EGT.

In a statement, EGT officials pointed out that the company employs workers from a different union to staff its terminal. The longshoremen's union says the jobs rightfully belong to them.

While the demonstrations were largely peaceful and isolated to a few gates at each port, local officials in the longshoremen's union and port officials or shipping companies determined that the conditions were unsafe for workers.

In Oakland, several hundred people picketed before dawn and blocked some trucks from going through at least two entrances.

A long line of big rigs sat outside one of the entrances, unable to drive into the port. Police in riot gear stood by as protesters marched in an oval and carried signs. Protesters cheered when they learned about the partial shutdown and then dispersed.