A group of port truck drivers thanked the “99 Percenters” on Monday for bringing attention to their profession, which they claim is rife with labor abuses.

"Occupy" protesters disrupted traffic at ports along the U.S. west coast on Monday, as a small number were arrested for seeking to shut down the major trade cargo hub, officials said.

The port truck drivers, who were affiliated with the Coalition for Clean & Safe Ports, stopped short of supporting the effort to shut down the ports. But they were "humbled and overwhelmed" by the attention the action brought. "Normally we are invisible," they said.

The biggest action was in Oakland, California where the anti-Wall Street demonstrators closed the major U.S. port for 24 hours last month, as protests were called from southern California up to Alaska.

Hundreds of demonstrators marched on the port early in the day, at one point preventing trucks from entering or leaving a couple of gates. And some 150 of 200 longshoremen were sent home to due to companies shutting docks due to safety concerns, said the International Longshore and Warehouse Union.

But port authorities said operations continued despite some disruption and delays.

"The companies we work for call us independent contractors, as if we were our own bosses, but they boss us around," the truck drivers said. "We receive Third World wages and drive sweatshops on wheels. We cannot negotiate our rates."

"Why are companies like SSA Marine, the Seattle-based global terminal operator that runs one of the West Coast's major trucking carriers, Shippers' Transport Express, doing this?" they continued. "Why would mega-rich Maersk, a huge Danish shipping and trucking conglomerate that wants to drill for more oil with Exxon Mobil in the Gulf Coast conduct business this way too?"

"To cheat on taxes, drive down business costs, and deny us the right to belong to a union, that's why."

Despite the hardships, they did not want to quit their jobs. The drivers would rather stick together and transform the industry from within by organizing themselves.

"Nowadays greedy corporations are treated as 'people' while the politicians they bankroll cast union members who try to improve their workplaces as 'thugs,'" they said.

"But we believe in the power and potential behind a truly united 99%. We admire the strength and perseverance of the longshoremen. We are fighting like mad to overcome our exploitation, so please, stick by us long after December 12."

In Long Beach, south of Los Angeles, two people were arrested after protesters marched on the port terminal of SSA Marine, a company 51 percent owned by Goldman Sachs, a key target of the Occupy Wall Street movement.

But by early afternoon the Port of Long Beach said there had been "minimal impact to port operations" during the rain-soaked demonstration by several hundred protesters at one of the world's largest shipping ports.

"Most freeways, bridges and port access routes remained open, and all shipping terminals were operational during the protest," a port statement said.

Further north in Portland, Oregon, where protesters also began demonstrations before dawn, two people were arrested for possession of weapons, and the port was partially closed down, according to local media.

In Seattle, Washington state, demonstrators planned rallies later in the day, according to organizers. There were no immediate reports of protest actions in Anchorage, Alaska.

In Oakland, across the Bay from San Francisco, more protesters were expected later in the day, organizers said.

Authorities in the northern California city wrote an open letter to protesters urging them not to shut down a port which handles some $39 billion in imports and exports per year.

"The port is connected to over 73,000 jobs in the region and more than 800,000 across the country. These are not just numbers. These are good jobs held by real working people and working families," it said.

The loosely organized, left-leaning Occupy Wall Street protesters insist they are exercising their freedom of speech in the run-up to November 2012 national elections.

Protest camps sprung up in recent months across the United States from New York to Los Angeles, though many have been closed down by officials wielding varying degrees of force.

With reporting by Eric W. Dolan