UNITED STATES President Donald Trump threatened on Thursday to invoke an 1807 law and deploy troops against Minneapolis protesters who have been confronting federal enforcers of his administration’s immigration crackdown.

The threat came a day after a man was shot and wounded by an immigration officer who had allegedly been attacked with a shovel and broom handle.

That shooting further heightened fear and anger that has radiated across the city since Immigration and Customs Enforcement (ICE) agent Jonathan Ross fatally shot Renee Good in the head on January 7.

Mr Trump has repeatedly threatened to invoke the rarely used Insurrection Act to deploy military forces or federalise the National Guard for domestic law enforcement.

In 2020 he threatened to use the act to stop protests after George Floyd was killed by Minneapolis police and in recent months has threatened to use it against immigration protests.

The increasingly authoritarian president said: “If the corrupt politicians of Minnesota don’t obey the law and stop the professional agitators and insurrectionists from attacking the patriots of ICE, 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.”

Presidents have invoked the law more than two dozen times, most recently in 1992 by then-president George H W Bush to pacify Los Angeles.

“I’m making a direct appeal to the president: Let’s turn the temperature down. Stop this campaign of retribution. This is not who we are” Governor Tim Walz, a Democrat, said on social media.

Minnesota Attorney General Keith Ellison said he would challenge any such action in court.

He’s already suing to try to stop the surge by the Department of Homeland Security, which says officers have arrested more than 2,500 people since November 29.

“This is an impossible situation that our city is presently being put in and at the same time we are trying to find a way forward to keep people safe,” Minneapolis Mayor Jacob Frey said on Wednesday.

The American Civil Liberties Union of Minnesota has also filed a class-action case on behalf of three people who said they were questioned or detained in recent days.

The case says two are Somali and one is Hispanic; all three are US citizens. The lawsuit seeks an end to what the ACLU describes as a practice of racial profiling and warrantless arrests.

The government did not immediately comment.