OAKLAND, Calif. -- The political battle over sanctuary cities has exploded into a public feud between the head of Immigration and Customs Enforcement (ICE) and Libby Schaaf, the mayor of Oakland, California. It started when the mayor tipped off residents about a federal roundup of people living in the U.S. illegally.

Reaction to the mayor was swift. Some called her office directly, while others posted on Facebook.

"People like you make this country much more dangerous," one post read.

A video shows one of the 150 undocumented immigrants being arrested in a multi-day, targeted sweep throughout Northern California, including Oakland.

Acting ICE Director Thomas Homan didn't hold back Wednesday.

"It's beyond the pale," Homan said. "I've been doing this for 34 years and this is a whole new low -- to intentionally warn criminals that law enforcement is coming. I just can't believe it happened."

"She gave them warning," he said. "And there's 800 that we were unable to locate because of that warning."

Oakland Mayor Libby Schaaf looks on during an assembly at Edna Brewer Middle School about the U.S. Constitution on January 19, 2018 in Oakland, California. Justin Sullivan/Getty Images

At Oakland City Hall, the mayor was unapologetic about tipping people off to the recent roundup. She said she's even willing to go to jail to protect Oakland's sanctuary city status.

"Every day as the mayor of Oakland I make decisions that are criticized. That comes with the job," she said.

CBS News pointed out that she is being accused of protecting people with criminal records.

"What I did was my job as the mayor of Oakland and reflective of the values of the people that I represent," she responded.

Under President Trump, immigration arrests are up 42 percent compared to under former President Obama. While criminal arrests under both administrations were about the same, 24,443 vs. 25,626, non-criminal arrests -- 3,121 vs. 13,548 -- saw a 334 percent spike under Mr. Trump.

Hundreds of protesters took to the streets of San Francisco on Wednesday.

Juan Pierto, an undocumented 25-year-old who has been living in the U.S. for 17 years, said depression is rising in his family.

"Some don't want to go out of their houses and that's no way to live," he said.

ICE said deportations will continue as planned. As for tipping off her community, Schaaf says she'll do it again.