US President Donald Trump Thursday threatened to deploy US military forces to respond to protests in Minnesota, writing that he would "institute the Insurrection Act" if the situation deteriorated in a social media post.

"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," ​Trump ​wrote on Truth Social.

Tensions escalated in Minneapolis on Wednesday night when a federal officer shot and injured a man in the leg after he attacked officers with a shovel and a broom during a targeted traffic stop.

The incident came a week after an American woman, Renee Nicole Good, was killed by an Immigration and Customs Enforcement (ICE) officer in the same city, sparking protests across major US cities.

What is the Insurrection Act?

The Insurrection Act of 1807 allows the US president to deploy the military or federalize National Guard troops to enforce the law, specifically in the face of rebellion or other domestic instances of violence.

The modern-day Insurrection Act is an amalgamation of statutes passed between 1792 and 1871 outlining the role of US military forces in domestic law enforcement.

The law has been sparingly used and was last invoked in 1993 by President George H.W. Bush to quell riots in Los Angeles after local officials requested assistance.

Supreme Court refused to allow Trump to send National Guard troops, a defeat for president

Trump sparked backlash when he sent National Guard troops to Los Angeles last June, without the governor's request or support, as part of his efforts to clamp down on immigration.

He also sent federal troops to Washington, DC, and Memphis, Tennessee, and ordered the deployment of troops to Chicago and Portland. But his push to deploy National Guard troops faced numerous legal challenges.

Ultimately, in December, the Supreme Court ruled that Trump could not deploy troops in the Chicago area over the objections of Illinois officials.

Trump said on January 1 he was backing down from his efforts to deploy the National Guard to the Democratic-led cities of Chicago, Los Angeles and Portland for now, without mentioning the ruling.

Edited by: Louis Oelofse