Federal prosecutors open investigation into Walz, Frey over alleged impeding of law enforcement

Two sources familiar confirmed the probe, though no additional details about the investigation have been publicly released.

Sources said the investigation is in early stages, and it is unclear if it will result in any criminal charges.

U.S. Deputy Attorney General Todd Blanche told Fox News the duo's anti-ICE rhetoric was teetering on a federal crime.

"When the governor or the mayor threaten our officers, when the mayor suggests that he's encouraging citizens to call 911 when they see ICE officers, that is very close to a federal crime," Blanche said.

Walz responded to the news by accusing the Trump administration of "weaponizing the justice system."

Frey also weighed in on social media, asserting he "will not be intimidated."

Frey's office told Fox News Digital they have not yet heard from the federal government.

"America depends on leaders that use integrity and the rule of law as the guideposts for governance," Frey's office wrote in a statement to Fox News Digital. "Neither our city nor our country will succumb to this fear. We stand rock solid."

"America depends on leaders that use integrity and the rule of law as the guideposts for governance. Neither our city nor our country will succumb to this fear. We stand rock solid."

The White House's Rapid Response 47 team criticized Walz following a statewide address Wednesday, where he called for ICE agents to be prosecuted.

"Help us establish a record of exactly what's happening in our communities. You have an absolute right to peacefully film ICE agents as they conduct these activities," Walz said. "So, carry your phone with you at all times. And if you see these ICE agents in your neighborhood, take out that phone and hit record.

"Help us create a database of the atrocities against Minnesotans, not just to establish a record for posterity. But to bank evidence for future prosecution."

Frey called for peace on Wednesday, just days after telling ICE to "get the f--- out" of the city. 

"If the corrupt politicians of Minnesota don't obey the law and stop the professional agitators and insurrectionists from attacking the Patriots of I.C.E., who are only trying to do their job, I will institute the INSURRECTION ACT, which many Presidents have done before me, and quickly put an end to the travesty that is taking place in that once great State," Trump wrote in the post.

The Insurrection Act, which allows the president to deploy the military to suppress rebellions and enforce federal laws, has not been invoked since the 1992 Los Angeles riots.

Fox News Digital's Greg Norman-Diamond contributed to this report.