Agents from the Department of Homeland Security raided the home of Minnesota Rep. Ilhan Omar on Monday morning, the Department of Justice confirmed in a statement, once again thrusting a vocal critic of President Donald Trump under the microscope of federal law enforcement.

“Today in the Washington, D.C. area, Homeland Security Investigations executed a judicially authorized search warrant secured by the Department of Justice,” a Justice Department spokesperson said in response to a question about a search at Omar’s home. “This enforcement action is part of an ongoing federal criminal investigation.”

A senior Trump administration official granted anonymity to discuss an ongoing investigation told POLITICO that Monday’s search is related to Omar’s immigration paperwork.

In a social media post, Omar called the search “just the latest escalation in his campaign of political intimidation” against her.