SAN FRANCISCO, June 21 (Xinhua) -- Mayors of sanctuary cities in San Francisco Bay Area Friday denounced the federal government's planned deportation operations targeting undocumented immigrants, which could begin on Sunday.

San Francisco Mayor London Breed slammed the potential raids by U.S. Immigration and Customs Enforcement (ICE) agents, ordered by President Donald Trump, on up to 2,000 migrant families.

"It is unconscionable that the federal administration is targeting innocent immigrant families with secret raids that are designed to inflict as much fear and pain as possible," she said in a statement.

Breed vowed to uphold the values of diversity and inclusiveness by San Francisco being a sanctuary city that "stands up for all our residents and neighbors."

We will continue to remain vigilant and offer services for all immigrants through the Office of Civic Engagement and Immigrant Affairs," she said.

Trump has directed ICE to kick off predawn raids on Sunday on the migrant families facing deportation orders in up to 10 U.S. cities including San Francisco, Los Angeles, Houston, Chicago, Miami and other major immigration destinations.

ICE "will begin the process of removing the millions of illegal aliens who have illicitly found their way into the United States. They will be removed as fast as they come in," Trump tweeted earlier.

Mayor Libby Schaaf of Oakland City, another sanctuary city in the Bay Area, reached out to residents, asking them to remain calm and well prepared in facing the potential ICE operations.

She told a press conference late Friday that she has no specific information about the raids in the city for the moment, but she "wants to assure members of my community not to panic, know your rights, and to use your local resources. You are in a community where you are respected, supported, and appreciated."

"This is not an appropriate use of executive power or elective power and I hope the American people hold him accountable," Schaaf said, referring to Trump's instruction to start the deportation raids.

Sam Liccardo, Mayor of San Jose the Silicon Valley city, expressed firm objection to the Trump administration's deportation policy, saying that the San Jose Police Department will not participate in ICE enforcement activity.

"In San Jose, we reject this administration's politics of fear and exclusion, which is tearing families apart. It's important for all members of our community -- regardless of immigration status -- to know they have rights," he tweeted.

He asked local residents to report the location of ICE activity, description of ICE vehicles, any badge numbers, photos, or other information to the Rapid Response Network, so that the city can offer "appropriate" legal help to those to be impacted by the ICE raids.

In February, ICE sent some 2,000 letters to families who already had received final orders of removal by courts in absentia, asking them to self-report to local ICE offices by March to comply with the orders, U.S. media reported.

Once arrests take place, the families will likely be moved to ICE family residential detention centers as the agency works with consulates to obtain travel documents, according to the media reports.