Online video showed hundreds of protesters gathered in Lafayette Park just outside the White House, chanting "No justice, no peace." One protester sprayed the Freedman's Bank Building while some other protesters clashed with Secret Service personnel, witnesses said.

The doors to the White House briefing room have also been locked and Secret Service officers are not letting anyone off White House grounds, local media reported.

"Secret Service personnel are currently assisting other law enforcement agencies during a demonstration in Lafayette Park. In the interest of public safety we encourage all to remain peaceful," the Secret Service tweeted.

Floyd, aged 46, died on Monday evening shortly after Derek Chauvin, a white police officer, held him down with a knee on his neck though he repeatedly pleaded, "I can't breathe," and "please, I can't breathe." Chauvin was arrested and charged with three-degree murder and manslaughter earlier on Friday.

Minneapolis Mayor Jacob Frey on Friday imposed a mandatory nighttime curfew beginning Friday night following three straight nights of growing protests and violence in the biggest city in U.S. Midwest state Minnesota.

However, protests over Floyd's death continued on Friday night in Minneapolis and a number of other cities, local media reported, saying that more protests are expected to take place across the country through the weekend.