US Attorney General William Barr has accused "extremist agitators", foreign interests of exploiting the nationwide protests against the murder of George Floyd.

"We have seen evidence that Antifa and other similar extremist groups, as well as actors of a variety of different political persuasions, have been involving in instigating and participating in violent activity," Barr told at a press conference.

Notably, the internal intelligence assessment conducted by the US Department of Homeland Security, three days before, found that the sporadic incidents of violence that took place at the protests were carried out by opportunists and not organised extremists.

Trump accused the anti-fascist movement ANTIFA for the violent protests that took place in various parts of the country. Meanwhile, federal prosecutors in Las Vegas on Wednesday charged three members of the far-right "Boogaloo" movement for plans to cause violence and destruction during the ongoing protests.

Soon after Floyd's death in police custody on May 25, the twin cities of Minneapolis and St. Paul erupted in massive protests which later on spread all across the country. 

The official post mortem report of Floyd revealed that the cause of death was due to 'neck compression'. George died of "cardiopulmonary arrest complicating law enforcement subdual, restraint, and neck compression," and the way of his death was "homicide," the Hennepin County Medical Examiner in Minneapolis announced in a statement.

Other crucial health conditions of Floyd were also listed as "arteriosclerotic and hypertensive heart disease; fentanyl intoxication; recent methamphetamine use."

The Trump administration has ordered military units to step in and quell the protests. Military helicopters flew low over the nation’s capital and National Guard units moved into many cities, as protestors gathered to express their anger against the systemic racism prevalent in the American policing system.

Trump, while addressing himself as the "law and order" president, said that he was deploying thousands of "heavily armed" soldiers and cops to prevent further protests in Washington.

On Sunday, as many as 40 cities and Washington D.C., imposed curfews amid the relentless protests against the death of George.