LOS ANGELES >> Thousands of people protested Monday in Los Angeles against President Donald Trump’s immigration crackdown, and a handful of activists in San Francisco tried to block cars from entering and leaving the city’s main federal immigration control building.

Waving American flags and signs reading “love not hate,” the Los Angeles demonstrators used the May Day event usually aimed at promoting worker rights to express their ire against Trump’s plans to restrict immigration.

Honduran immigrant Selvin Marinez took the day off from his job waxing casino floors to protest, a U.S. flag draped over his shoulders.

“We hope to get to be respected as people, because we are not animals, we are human beings,” said Martinez, who said he fled his country because of violence 14 years ago.

Martinez, 30, said he has a U.S. work permit but fears immigration agents may still try to deport him. He worried that showing up to protest could draw attention to himself but felt it was important to do so.

“It makes you scared, but making our rights known is stronger than the fear,” he said.

Kathleen Takata, a retired consultant, had never marched on May Day before but felt compelled to do so against Trump’s plans for a border wall on the U.S-Mexico border and travel ban against people from certain countries.

“I’ve been energized ever since the election to become a very active citizen,” she said. “I think for too long I took for granted the responsibilities and privileges of U.S. citizenship.”

Trump’s efforts are opposed by many state and local leaders in heavily-Democratic California, which in recent years has adopted immigrant-friendly policies such as issuing driver’s licenses regardless of immigration

Elsewhere in California, four protesters in downtown Oakland were arrested for chaining themselves together to block the entrance to a county administration building to demand an end to what they called collaboration between county law enforcement and U.S. Immigration and Customs Enforcement.

Alameda County Sheriff’s Office spokesman Sgt. Ray Kelly contested the protesters’ claims, saying the county’s officers must cooperate with federal immigration agents who have federal warrants to execute.

. “There are no police officers in California that are involved in front-line immigration enforcement,” he said. “It’s not our job or our mission to do the federal government’s work. We have enough on our hands with violent crime and all these other community issues.”

Several hundred protesters gathered in San Francisco, and a handful staged a sit-down at the vehicle entrance for the immigration agency’s building to try to prevent access. But no cars were seen entering or exiting.

“More and more workers are actually afraid to speak up, to access rights that they have whether or not they’re documented, because of a lot of the fear mongering that’s occurring that this building, ICE, represents and that’s why we’re here today,” said Lucia Lin, a an organizer with the Chinese Progressive Association.

Union members typically march globally on May 1 in support of workers’ rights. The event in 2006 became a rallying point in the U.S. in support of immigrants when more than 1 million people marched against a proposed immigration enforcement bill.

The demonstrations waned in subsequent years as groups took different approaches on immigration, including lobbying and voter registration.

In San Francisco, immigrant rights groups have joined with Muslim organizations and women’s advocates, said Roberto Hernandez, organizer for the city’s May 1 Coalition.

A similar coalition emerged in Los Angeles, said Jorge-Mario Cabrera, a spokesman for the Coalition for Humane Immigrant Rights.