President Donald Trump said on Monday he was deploying thousands of heavily armed soldiers and law enforcement to stop violence in the US capital and vowed to do the same in other cities if mayors and governors failed to regain control of the streets.

As Trump spoke in the Rose Garden of the White House, live television images showed police firing tear gas to dispel demonstrators in Lafayette Park, across the street.

“Mayors and governors must establish an overwhelming law enforcement presence until the violence has been quelled,” Trump said. “If a city or state refuses to take the actions that are necessary to defend the life and property of their residents, then I will deploy the United States military and quickly solve the problem for them.”

The demonstrations, largely peaceful during the day but turning violent after dark, have erupted over the death of George Floyd, a 46-year-old African American who died in Minneapolis police custody after being pinned beneath a white officer’s knee for nearly nine minutes.

A second autopsy ordered by Floyd’s family and released on Monday found that his death was a homicide by “mechanical asphyxiation”, meaning some physical force interfered with his oxygen supply. The report says three officers contributed to Floyd’s death.

The Hennepin County Medical Examiner on Monday released details of its autopsy findings that also said Floyd’s death was a homicide caused by asphyxiation. The county report added that Floyd suffered cardiopulmonary arrest while being restrained by police and that he had arteriosclerotic and hypertensive heart disease, fentanyl intoxication and recent methamphetamine use.

The new findings emerged after Trump spoke to the governors earlier in the day.

“You have to dominate,” he told them in a private call obtained by Reuters. “If you don’t dominate, you’re wasting your time – they’re going to run over you, you’re going to look like a bunch of jerks.”

Trump said the federal government was going to clamp down “very strong” on the violence. National Guard troops were deployed near the White House early Monday evening.

Dozens of cities across the United States remain under curfews at levels not seen since riots that broke out following the 1968 assassination of Martin Luther King Jr. The National Guard were deployed in 23 states and Washington, D.C..

One person was killed in Louisville, Kentucky, overnight where police and National Guard troops returned fire while trying to disperse a crowd. Police in Chicago fielded some 10,000 calls for looting, Mayor Lori Lightfoot said.

The unrest, which erupted as the country was easing sweeping lockdowns to stop the spread of the coronavirus, began with peaceful protests over Floyd’s death.

Derek Chauvin, a since-fired 44-year-old officer, has been arrested and charged with third-degree murder and second-degree manslaughter.

On Monday, dozens of people paid their respects to Floyd outside Cup Foods, the scene of his death. Visitors left flowers and signs honouring Floyd. A little girl wrote, “I’ll fight with you”, in aqua blue chalk on the road.

“This is therapeutic. My heart was real heavy this morning, so I came down extra early and when I got here, the heaviness lifted,” said Diana Jones, 40, the mother of four children. “This right here lets me know that things are going to be OK.”

Terrence Floyd, the victim’s brother, told the gathering he wanted people to get educated, vote and not destroy their own communities. “Let’s do this another way,” he said.

Floyd’s death was the latest to prompt an outcry over racism in law enforcement. It reignited outrage across a politically and racially divided country that has been hit hard by the coronavirus pandemic, with African Americans accounting for a disproportionately high number of cases.

The US Justice Department has directed the Bureau of Prisons to send riot-control teams to Miami and Washington, D.C., to help manage the protests, a department official told reporters.

Department investigators are interviewing people arrested during protests who might face federal charges for such offences as crossing state lines to incite violence, the official said.

Many cities affected by the unrest are allowing some businesses to reopen after more than two months of stay-at-home orders to stem a pandemic that has killed more than 104,000 people and left 40 million others jobless.

Trump has condemned the killing of Floyd and promised justice but has described protesters as “thugs”.

Critics accuse the Republican president, who is seeking re-election in November, of stoking conflict and racial tension when he should be uniting the nation and addressing underlying issues.

Democratic presidential candidate Joe Biden met with black community leaders in a church and said he would create a police oversight board within his first 100 days in the White House if elected.

(FRANCE 24 with REUTERS)