The U.S. Department of Justice has sued the State of Illinois and the City of Chicago for attempting to protect undocumented immigrants from federal immigration officers, The Washington Post reported.

The suit is the first of its kind and was filed in the U.S. District Court for Northern District of Illinois, The Washington Post reported. The suit alleges that the sanctuary laws of the state and the city were designed to interfere with the deferral government’s enforcement of immigration law.

However, Chicago is a “sanctuary city,” meaning they have laws in place to protect undocumented immigrants from possible deportation, The Washington Post reported.

Illinois also has several laws in place to protect undocumented immigrants, such as the TRUST Act, which prevents local law enforcement from holding immigrants without a court warrant, Illinois Governor J.B. Pritzker said.

“[The TRUST Act] has always been compliant with federal law and still is today,” Pritzker said in a statement.

Last month, multiple immigration advocacy groups filed lawsuits in Illinois against Immigration and Customs Enforcement to block the agency from carrying out operations in Chicago, The New York Times reported. Illinois has continued to defend their laws to protect immigrants, a spokesman said in an emailed statement.