Last Update 2:25 p.m. ET
OAKLAND, Calif. - Crowds of anti-Wall Street protesters stopped truck traffic Monday at two busy Port of Oakland gates as the movement converged on West Coast ports.
Several hundred people began picketing at the Port of Oakland before dawn and blocked at least two entrances. A long line of big rigs sat outside the gates, unable to drive into the port.
Police in riot gear monitored the scene as protesters marched in an oval and carried signs with messages such as "Labor and Occupy Unite," an invitation to the powerful dockworkers union join their push against corporate greed.
No major clashes with police were reported.
Longshoremen arriving for the morning shift at the two affected port terminals did not try to enter due to what union officials said were safety concerns. Some said they weren't willing to cross the demonstrators' picket lines.
Port spokesman Isaac Kos-Read said the protests were causing sporadic disruptions but all port terminals remained in operation.
The actions were part of a coordinated effort by the Occupy Wall Street movement to shut down major ports along the West Coast and cut into corporate profits.
The protesters are targeting the locations because they believe American ports have become "economic engines for the elite." They are most upset by two West Coast companies - giant West Coast port operator SSA Marine and grain exporter EGT - that they believe epitomize the big corporations that make up the "1 percent."
Goldman Sachs owns a major stake in SSA Marine, and the bank has been a repeated target of Occupy protesters since the movement began. The two port companies have also engaged in high-profile clashes with union workers lately, and the Occupy protesters want to stand up for the workers.
At the port in Longview, Wash., longshoremen have gone home for the day, essentially shutting down the terminal. ILWU spokeswoman Jennifer Sargent said the union sent their workers home out of concerns for their "health and safety."
Port of Longview spokesman Ashley Helenberg said the decision to shut down operations was made by both the port and the union. She said about 20 shifts were affected. The port had one vessel to work on Monday.
Oakland port spokesman Robert Bernardo reported some disruptions to truck traffic but that maritime operations continue there.
Port and city officials and International Longshore and Warehouse Union leaders have criticized the plan, saying that the action will hurt port workers.
The action is part of a coordinated Occupy shutdown of West Coast ports. Organizers said the shutdown is, in part, to show support for dockworkers embroiled in a labor dispute in Washington.
But the International Longshore and Warehouse Union's president said the union has not voted to support the shutdown.
"Support is one thing; organization from outside groups attempting to co-opt our struggle in order to advance a broader agenda is quite another," said ILWU president Robert McEllrath.
Oakland Mayor Jean Quan said, "The port has asked us to keep it open. We're going to try to do our best to keep it open. As the mayor of the city, I'd ask people, 'Why are you doing this?'"
"A lot of the union leaders at the port and the commissioners are asking the community to really think if this will help the 99 percent," Quan said. "The port could potentially lose business."
Responding to charges that the blockade will hurt workers, one protester marching to the port Monday morning told CBS Station KPIX, "Business is how we're being exploited. If we don't shut it down, how do you expect us to change anything?"
One ILWU member, Clarence Thomas, told KPIX, "If it were not for labor and working people, we would not have the 8-hour work day; children would still be exploited," "We would not have health care benefits. And the only way we got that was through struggle."
Occupy Oakland previously shut down the Port of Oakland overnight during a daylong "general strike" action on Nov. 2.
Today's action has been endorsed by Occupy movements from Anchorage to San Diego, with each city planning a shutdown of its own.
In Southern California, as many as 400 demonstrators marched on the Port of Long Beach, to a dock facility owned by SSA Marine. Beating drums and waving flags, dozens of protesters, gathered outside a fenced area at the port, part of a sprawling complex that spans parts of Los Angeles and Long Beach.
Several union and non-union workers told CBS Station KCBS they will treat the march as a picket line.
Police repeatedly warned that they faced arrest if they crossed the fenced area. Officers later started pushing the protesters further back. They spilled into the street, blocking access to the pier and holding up truck traffic. At least one person was taken into custody.