A day after an immigration raid rattled MacArthur Park—a heavily immigrant neighborhood just west of downtown Los Angeles—Mayor Karen Bass, City Attorney Hydee Feldstein Soto, Los Angeles County Board of Supervisors, and other regional leaders announced Tuesday that they’re joining a lawsuit to block what they call unconstitutional immigration enforcement tactics in Southern California.

City of Los Angeles, Los Angeles County, and the cities of Pasadena, Santa Monica, Culver City, Pico Rivera, Montebello, Monterey Park and West Hollywood filed a motion to intervene in Perdomo v. Noem, a class-action lawsuit originally brought by the American Civil Liberties Union in Southern California and a few other civil rights groups on behalf of five California residents.

The plaintiffs argue federal agents have conducted unlawful stops, raids and arrests without reasonable suspicion or probable cause—often targeting people based on perceived ethnicity—and have used disproportionate force in immigration enforcement. The lawsuit also describes alleged detention in federal facilities without access to attorneys.

“It is critical that we use every single venue, every single possibility of seeking justice, and that’s what we’re doing today,” Bass said at a press conference at City Hall on Tuesday afternoon. “And I do hope that the courts especially issue this injunction and stop this.”

L.A. County Supervisor Hilda Solis announced Tuesday afternoon that the county joined the city’s efforts to address allegedly warrantless arrests and seizures caused by ICE raids, authorized by DHS.

“Today, as a result of that motion, the County of Los Angeles is joining the city of Los Angeles to intervene in a federal class action lawsuit against the Trump administration,” Solis said in a statement. “For the past month, we’ve seen individuals picked up at car washes and Home Depot parking lots, then simply disappear without warrants, probable cause, or due process.”

Three of the original plaintiffs are Pasadena men who say they were stopped by federal agents in June while waiting for a bus to work. The men, Pedro Vasquez Perdomo, Carlos Alexander Osorto and Isaac Villegas Molina, were then held in the basement of the downtown federal building.

Pasadena Mayor Victor Gordo, the city’s first Latino mayor, said Pasadena joined the motion because of what he called blatant constitutional violations.

“I’m offended by the federal government on behalf of our city,” Gordo said. “As an attorney, I’m offended by the complete violation of due process and our Constitutional rights. As an immigrant, I’m offended by the immorality and the plain dismissal of people who are here to contribute.”

Feldstein Soto said the intervention aims to defend the city’s own rights as well as its residents’ rights.

“We as jurisdictions not only support our residents in stopping these unconstitutional practices, but we in effect assert our own rights under the Tenth Amendment and as jurisdictions that ultimately have local control over our police powers,” she said.

Feldstein Soto said the city is intervening to defend its own authority over policing and public safety, warning that federal immigration sweeps have disrupted local businesses, eroded public trust and undermined the city’s ability to govern effectively.

“These unconstitutional roundups and raids cannot be allowed to continue,” Feldstein Soto said. “They cannot become the new normal.”

She also stressed the lawsuit doesn’t seek to block immigration enforcement entirely.

“Let me say that again, immigration enforcement will continue,” Feldstein Soto said. “There is nothing about the TRO (temporary restraining order), there is nothing about the position of the local jurisdictions here that seeks to impede or intervene with the Constitutional enforcement of the laws of the land. What we are objecting to is the unconstitutional manner in which this administration is seeking to enforce those laws.”

The Los Angeles City Council last week unanimously approved a motion directing the City Attorney’s Office to pursue legal action aimed to protect Angelenos by seeking “injunctive relief from unconstitutional searches, seizures and detentions.”

Feldstein Soto said Tuesday the motion and the lawsuit are parallel efforts.

“We are doing it,” she said. “We were doing it before. We were doing it during, and we’ll keep doing it.”

The city’s move followed a dramatic federal operation in MacArthur Park on Monday morning. Witnesses described agents on horseback and armored vehicles moving through MacArthur Park. Immigration advocates had urged vendors and residents to avoid the area ahead of time, leaving it largely empty when officers arrived.

It remains unclear whether anyone was arrested. The Department of Homeland Security has declined to say how many people, if any, were taken into custody or to explain the purpose of the operation at the park.

The raid has quickly become one of the most visible flashpoints in escalating tensions between the federal government and California officials over immigration enforcement in sanctuary cities like Los Angeles. Local leaders have repeatedly opposed federal crackdowns and vowed to protect undocumented residents.

Bass and Gov. Gavin Newsom both called the MacArthur Park operation a political stunt meant to intimidate immigrant communities. Bass visited the park on Monday, joining a small crowd of onlookers. She reportedly spoke by phone with U.S. Customs and Border Patrol Protection’s Gregory Bovino, chief of the El Centro Sector, urging federal agents to leave.

Bovino, in remarks to FOX News on Monday, dismissed her request. “I don’t work for Karen Bass,” he said. “Better get used to us now, ’cause this is going to be normal very soon. We will go anywhere, anytime we want in Los Angeles.”

Tensions over immigration enforcement have been building for weeks. Last month, the Trump administration sued the City of Los Angeles, accusing it of violating federal law with its “sanctuary city” policies. In response, the City Council unanimously directed the City Attorney’s Office to pursue legal action to protect Angelenos from “unconstitutional searches, seizures and detentions.”

This publication has reached out to the Department of Homeland Security for comments.