U.S. Immigration and Customs Enforcement acting director Thomas Homan has condemned a sanctuary city mayor in California for warning illegal immigrants of potential raids, castigating her decision as "political" and "reckless."

“Sanctuary jurisdictions like San Francisco and Oakland shield dangerous criminal aliens from federal law enforcement at the expense of public safety," Homan wrote in a statement issued Tuesday.

"Because these jurisdictions prevent ICE from arresting criminal aliens in the secure confines of a jail, they also force ICE officers to make more arrests out in the community, which poses increased risks for law enforcement and the public," he continued. "The Oakland mayor’s decision to publicize her suspicions about ICE operations further increased that risk for my officers and alerted criminal aliens – making clear that this reckless decision was based on her political agenda with the very federal laws that ICE is sworn to uphold."

Libby Schaaf released a statement Saturday saying she felt it was her “duty and moral obligation" as the mayor of Oakland to give illegal immigrants "fair warning" of the "imminent" raids.

Schaaf also reminded Oakland citizens it was against California law for business owners to assist ICE officers in immigration enforcement efforts.

More than 150 people allegedly in violation of federal immigration laws were arrested by ICE as part of the raids and now face possible prosecution or deportation, according to Homan's statement.

The raids follow President Trump threatening to pull federal immigration officers and Border Patrol agents from California over the state's sanctuary policy.