MINNEAPOLIS (AP) — The Justice Department is investigating whether Minnesota Gov. Tim Walz and Minneapolis Mayor Jacob Frey have impeded federal immigration enforcement through public statements they have made, according to two people familiar with the matter.

The investigation focused on potential violation of a conspiracy statute, the people said.

The people spoke to The Associated Press on condition of anonymity because they were not authorized to discuss a pending investigation by name.

In response to reports of the investigation, Walz said in a statement: “Two days ago it was Elissa Slotkin. Last week it was Jerome Powell. Before that, Mark Kelly. Weaponizing the justice system and threatening political opponents is a dangerous, authoritarian tactic.”

Senators Kelly and Slotkin, U.S. senators Arizona and Michigan, are under investigation from the Trump administration after appearing with other Democratic lawmakers in a video urging members of the military to resist “illegal orders,” while the administration has launched a criminal investigation of Powell, the federal reserve chair.

Walz’s office said it has not received any notice of an investigation.

Frey described the investigation as an attempt to intimidate him for “standing up for Minneapolis, our local law enforcement, and our residents against the chaos and danger this Administration has brought to our streets.”

“I will not be intimidated,” he added. “My focus will remain where it’s always been: keeping our city safe.

The investigation comes during a weekslong immigration crackdown in Minneapolis and St. Paul that the Department of Homeland Security has called its largest enforcement operation, resulting in more than 2,500 arrests.

The operation has become more confrontational since the fatal shooting of Renee Good on Jan. 7. State and local officials have repeatedly told protesters to remain peaceful.

The U.S. attorney’s office in Minneapolis did not immediately comment.

In a post on the social media platform X following reports of the investigation, Attorney General Pam Bondi said: “A reminder to all those in Minnesota: No one is above the law.” She did not specifically mention the investigation.

State authorities, meanwhile, had a message for any weekend protests against the Trump administration’s unprecedented immigration sweep in the Twin Cities: avoid confrontation.

“While peaceful expression is protected, any actions that harm people, destroy property or jeopardize public safety will not be tolerated,” said Commissioner Bob Jacobson of the Minnesota Department of Public Safety.

His comments came after President Donald Trump backed off a bit from his threat a day earlier to invoke an 1807 law, the Insurrection Act, to send troops to suppress demonstrations.

“I don’t think there’s any reason right now to use it, but if I needed it, I’d use it,” Trump told reporters outside the White House.