The Trump administration sued the city of Los Angeles on Monday seeking to topple its so-called sanctuary city policy, saying its stance blocks immigration enforcement.

“The City of Los Angeles’ Sanctuary City laws are illegal. Those laws and policies are designed to and in fact do interfere with and discriminate against the Federal Government’s enforcement of federal immigration law in violation of the Supremacy Clause of the United States Constitution,” the Department of Justice wrote in the suit.

“The challenged law and policies of the City of Los Angeles obstruct the Federal Government’s enforcement of federal immigration law and impede consultation and communication between federal, state, and local law enforcement officials.”

The lawsuit is the fourth from the administration challenging such policies. Similar litigation targeting sanctuary cities and states has been filed in Chicago and Illinois, Colorado and New Jersey.

But the Los Angeles suit follows a series of widespread immigration raids that resulted in protests as well as clashes with law enforcement.

Trump sent in the National Guard and later the Marines to respond to the protests, a rare use of military might in response to demonstrations.

The city of Los Angeles did not immediately respond to a request for comment.

The suit includes several references to the election, including a campaign pledge by President Trump to deport immigrants and writing that the U.S. is “facing a crisis of illegal immigration.”

Los Angeles Mayor Karen Bass (D) has been highly critical of Trump’s actions in the city, saying it inflamed tensions and that the president was not staying true to his call to deport “the worst of the worst.”

“Why were there raids?” Bass said during a television appearance earlier this month. “We had been told that he was going to go after violent criminals. It wasn’t a drug den; it was a Home Depot.”