File - In this Tuesday, Feb. 7, 2017, photo released by U.S. Immigration and Customs Enforcement, foreign nationals are arrested during a targeted enforcement operation conducted by U.S. Immigration and Customs Enforcement (ICE) aimed at immigration fugitives, re-entrants and at-large criminal aliens in Los Angeles. A federal immigration official says about 800 people living in Northern California were able to avoid arrest because of a warning by Oakland Mayor Libby Schaaf. Thomas Homan, the Immigration and Customs Enforcement chief, told "Fox and Friends" Wednesday, Feb. 28, 2018, that what Schaaf did was "no better than a gang lookout yelling 'police' when a police cruiser comes in the neighborhood." (Charles Reed/U.S. Immigration and Customs Enforcement via AP, File)

File - In this Tuesday, Feb. 7, 2017, photo released by U.S. Immigration and Customs Enforcement, foreign nationals are arrested during a targeted enforcement operation conducted by U.S. Immigration and Customs Enforcement (ICE) aimed at immigration fugitives, re-entrants and at-large criminal aliens in Los Angeles. A federal immigration official says about 800 people living in Northern California were able to avoid arrest because of a warning by Oakland Mayor Libby Schaaf. Thomas Homan, the Immigration and Customs Enforcement chief, told "Fox and Friends" Wednesday, Feb. 28, 2018, that what Schaaf did was "no better than a gang lookout yelling 'police' when a police cruiser comes in the neighborhood." (Charles Reed/U.S. Immigration and Customs Enforcement via AP, File)

SAN FRANCISCO (AP) — About 800 “criminals” avoided immigration arrests because Oakland Mayor Libby Schaaf alerted the public to the surprise operation, an extraordinarily high number of missed targets, according to a federal official.

Thomas Homan, U.S. Immigration and Customs Enforcement’s acting director, told Fox News that the mayor’s warning on Twitter was “beyond the pale” and compared her to a gang lookout who tells people when a police car is arriving. Homan said the Justice Department is looking into whether Schaaf obstructed justice.

ADVERTISEMENT

The mayor’s unusual public warning last weekend came hours before the agency launched an operation in Northern California that resulted in more than 150 arrests as of Tuesday, according to the agency.

The agency declined to elaborate on the 800 who allegedly got away or answer other questions about the operation that began Sunday. Danielle Bennett, an agency spokeswoman, said more information would be released later in the week.

John Torres, the agency’s director during the end of George W. Bush’s administration and beginning of Barack Obama’s, said agents generally capture about 40 percent of people they target in such sweeps.

Targets often elude authorities because agents don’t have search warrants and advocacy groups have waged public awareness campaigns urging people not to open their doors. Other times, agents have outdated addresses or targets are not home.

It was unclear how many people would have eluded capture without the mayor’s warning but Homan squarely blamed her for 800 and said her actions jeopardized officer safety.

“There’s over 800 significant public safety threat criminals, these are people who are here illegally and committed yet another crime, been convicted of a crime,” he told Fox. “She gave them warning, and there’s 800 that we were unable to locate because of that warning, so that community’s a lot less safe than it would have been.”

Homan’s statement of 800 missed targets — plus the 150 arrests — in only three days suggests an unusually large operation by the agency’s standards. Two weeks ago, it arrested 212 in a five-day operation in the Los Angeles area. A Texas operation in February resulted in 145 arrests over seven days.

The agency said about half of the people arrested during the Northern California sweep have criminal convictions in addition to immigration violations, including convictions for assault, weapons offenses and driving under the influence. It is impossible to independently verify that claim because the agency refuses to name them. Its statement identified only one arrest by name.

Schaff on Saturday issued a statement on Twitter that she learned from “multiple credible sources” that an immigration operation was imminent in the San Francisco area, including Oakland, possibly within 24 hours.

The mayor, who is running for another term this year, defended her actions again on Wednesday, saying she was not tipped off by “official sources” and that she didn’t reveal specific locations.

Asked about Homan likening her to a gang lookout, she said the “Trump administration is trying to distract the American people, convince them that these immigrants are dangerous people. That could not be further from the truth and it is based in racism.”

Lara Bazelon, an associate law professor at the University of San Francisco, said it was highly unlikely that the mayor would be prosecuted.

“It’s a tall order for ICE to show that she was obstructing justice because they would have to show she knew they were going after specific people and I just don’t see the evidence for that,” she said.

The warring words are the latest sign of escalating tension between California officials and the Trump administration over immigration enforcement and “sanctuary” jurisdictions. Homan vowed that immigration agents would have a stronger presence in California since a state law took effect in January to sharply limit cooperation between state and local law enforcement and federal immigration authorities.

San Francisco Public Defender Jeff Adachi, who attended a protest outside the agency’s San Francisco office, said immigration officials did not respond to his demand that attorneys be allowed to interview people detained in the operation.

Booking logs at the Sacramento County jail show at least 12 people booked there by the agency on Sunday.

Dozens of protesters marching outside the agency’s offices in San Francisco after Homan spoke chanted, “Shut down ICE!” David Chiu, a Democratic state assemblyman, said Trump “has declared war on our immigrant communities.”

“We’re here to stand united and say we do not want him ripping apart our families, ripping apart our economy, ripping apart California,” he said.

Homan, in announcing the arrests late Tuesday, renewed his warning that California’s limits on cooperating with ICE in local jails will lead to a bigger presence of immigration agents on the streets.

“Sanctuary jurisdictions like San Francisco and Oakland shield dangerous criminal aliens from federal law enforcement at the expense of public safety,” he said.

Defenders of so-called sanctuary city practices say they improve public safety by promoting trust among law enforcement and immigrant communities and reserving scarce police resources for other, more urgent crime-fighting needs.

__

Spagat reported from San Diego. Associated Press writers Paul Elias and Terry Chea in San Francisco contributed.