OAKLAND (CBS SF) — In what may be an unprecedented move, Oakland’s mayor warned the city’s “most vulnerable” residents of a pending operation by the U.S. Immigration and Customs Enforcement (ICE) within the next 24 hours.

“I am sharing this information publicly not to panic our residents but to protect them,” Mayor Schaaf said in a statement Saturday night.

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Schaaf said she did not know the details of the ICE operation or exact locations.

In the statement, the mayor provided a link to a Centro Legal de la Raza’s website which offers information about legal rights and options for people facing detention.

“We understand ICE has used activity rumors in the past as a tactic to create fear; our intent is for our community to go about their daily lives without fear, but resiliency and awareness,” said Schaaf.

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According to Schaaf, Oakland schools, police officers and business owners are prohibited from assisting ICE agents.

“Oakland is a city of law-abiding immigrants and families who deserve to live free from the constant threat of arrest and deportation,” she said. “I believe it is my duty and moral obligation as Mayor to give those families fair warning when that threat appears imminent.”

KPIX 5 reached out to ICE for confirmation. ICE spokesperson James Schwabs said he wasn’t sure what Schaaf was referring to.

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“ICE conducts operations every day,” he said.