OAKLAND (CBS SF) – Four people were arrested early Monday after they blocked an entrance to the Alameda County Administration Building in the first of several May Day rallies in the Bay Area.

More than 100 protesters gathered at the building — chaining themselves to the doors and lying on the street — demanding an end to the county’s corroboration with the U.S. Immigration and Customs Enforcement. The protesters also were demanding the county not go forward with a planned expansion of Santa Rita Jail.

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Later Monday afternoon, about 1,000 demonstrators marched in Oakland’s Fruitvale District and then convened in San Antonio Park in East Oakland.

Elsewhere, thousands of workers and activists from across the Bay Area rallied and marched Monday in honor of International Workers Day, or May Day, and to support immigrant rights.

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In San Francisco several hundred people demonstrated at the Immigration and Customs Enforcement Office in downtown, closing down streets around the Sansome Street.

Those demonstrators then marched to a May Day rally at Justin Herman Plaza at the foot of Market St. Members of the Service Employees International Union and other workers’ group then held a march in support of immigrant rights to Civic Center Plaza.

In San Jose, hundreds of workers, including tech industry employees, turned out for a May Day rally at the Mexican Heritage Plaza on Alum Rock Ave.

In Concord, activists scheduled a May Day rally and march to begin at 4 p.m. at Meadow Homes Park at 1351 Detroit Ave. Participants will rally to defend immigrant rights and to call on city leaders to make Concord a sanctuary city.

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