Updated

May Day protests may disrupt the morning commute in major U.S. cities Tuesday as labor, immigration and Occupy activists rally support on the international workers' holiday.

Demonstrations, strikes and acts of civil disobedience are being planned around the country, including the most visible organizing effort by anti-Wall Street groups since Occupy encampments came down in the fall.

While protesters are backing away from a call to block San Francisco's Golden Gate Bridge, bridge district ferry workers said they'll strike Tuesday morning to shut down ferry service, which brings commuters from Marin County to the city. Ferry workers have been in contract negotiations for a year and have been working without a contract since July 2011 in a dispute over health care coverage, the Inlandboatmen's Union said.

A coalition of bridge and bus workers said they will honor the picket line, which may target an area near the bridge's toll plaza. Occupy activists from San Francisco and Oakland are expected to join the rally.

"We ask supporters to stand with us at strike picket lines on May Day and to keep the bridge open," said Alex Tonisson, an organizer and co-chair of the Golden Gate Bridge Labor Coalition.

Police say they are working with other area law enforcement agencies and have a plan in place for potential disruptions. They would not discuss specifics.

Across the bay in Oakland, where police and Occupy protesters have often clashed, officers are preparing for a long day as hundreds of "General Strike" signs have sprouted across town.

In New York City, where the first Occupy camp was set up and where large protests brought some of the earliest attention — and mass arrests — to the movement, leaders plan a variety of events, including picketing, a march through Manhattan and other "creative disruptions against the corporations who rule our city."

Organizers have called for protesters to block one or more bridges or tunnels connecting Manhattan, the city's economic engine, to New Jersey and other parts of the city.

The Occupy movement began in September with a small camp in a lower Manhattan plaza that quickly grew to include hundreds of protesters using the tent city as their home base. More than 700 people were arrested Oct. 1 as they tried to cross the Brooklyn Bridge.

The city broke the camp up in November, citing sanitary and other concerns, but the movement has held smaller events and protests periodically since then.

Elsewhere on the West Coast, Occupy Seattle has called for people to rally at a park near downtown Tuesday. Mayor Mike McGinn has warned residents there could be traffic delays and has said city officials have evidence — including graffiti and posters — that some groups plan to "commit violence, damage property and disrupt peaceful free speech activity."

In Los Angeles, Occupy is organizing a daylong "people's power and bike caravan" that will start from the four cardinal directions around the city in the morning, converging on downtown LA's financial district in the mid afternoon for an approximately 90-minute protest. The themes of the marches are foreclosures and police brutality.

In a website statement, Occupy LA promised the event will be "city-paralyzing" and "carnivalesque" with en route actions including a food giveaway in a South Los Angeles park, and mini-rallies outside the Veterans' Affairs and Bank of America buildings in West Los Angeles.

___

Associated Press writers Terry Collins in Oakland and Christina Hoag in Los Angeles contributed to this report.