1,600 active duty military troops have been moved to the Washington DC region from Fort Bragg in North Carolina and Fort Drum in New York.

CNN quoted a statement from Pentagon chief spokesman Jonathan Hoffman on June 3 (Singapore time), who confirmed that no active duty forces have been deployed within Washington DC itself.

However, "active duty elements are postured on military bases in the National Capitol Region." Hoffman said that this was a "prudent planning measure".

Added Hoffman:

"(The troops) are on heightened alert status but remain under Title X authority and are not participating in defence support to civil authority operations."

President Trump threatened to send in US military to cities with protests

Previously on June 2, President Donald Trump threatened to send the the US military to quell the unrest over the death of George Floyd if cities and states did not control the protests.

According to the BBC, Trump said he would deploy the army and "quickly solve the problem for them."

Deploying active duty military forces within the US itself is an exceedingly rare step.

According to the Washington Post, a law called the Posse Comitatus Act prohibits the use of the military for the purposes of law enforcement without specific authorisation from Congress.

However, a different law called the Insurrection Act allows the President to do so under certain circumstances.

The use of the Insurrection Act in US history

This Act was last invoked in 1992 by President George H. W. Bush in response to the riots over the beating of Rodney King in Los Angeles, California.

However, this was after Bush was asked to do so by the California's Governor at the time.

According to ABC, the Act was invoked by President Dwight D. Eisenhower in 1957 to allow the US Army's 101st Airborne Division to escort African-American students to the Little Rock Central High School in Arkansas.

It was also invoked by President John F. Kennedy and President Lyndon B. Johnson during the Civil Rights movement of the 1960s, to enforce civil rights laws and quell riots and protests.

Top image by Mandel Ngan on June 1 via Getty Images.