Violence has erupted in cities across the US on the sixth night of protests sparked by the death in police custody of African-American George Floyd.

Dozens of cities imposed curfews, but many people ignored them, leading to stand-offs and clashes.

Riot police faced off with protesters in New York, Chicago, Philadelphia, and LA, firing tear gas and pepper bullets to try to disperse crowds.

Police vehicles were set on fire and shops were looted in several cities.

The country is experiencing the most widespread racial turbulence and civil unrest since the backlash to the assassination of Martin Luther King in 1968.

The outpouring of anger began last Tuesday after a video showed Mr. Floyd being arrested in Minneapolis and a white police officer continuing to kneel on his neck even after he pleaded he could not breathe and fell unconscious.

The National Guard - the US reserve military force for domestic emergencies - said on Sunday that 5,000 of its personnel had been activated in 15 states and Washington, DC, where crowds once again gathered near the White House.

Demonstrators lit fire to buildings there, including a historic church known as the church of the presidents, and threw stones at riot officers. Police used tear gas in response.

In Louisville, Kentucky, a man was shot dead in a confrontation between protesters, police and the National Guard after midnight early on Monday. Shots were fired at police officers and guard troops as they moved to disperse a crowd in a car park and "returned fire", leaving one man dead, Louisville Metro Police said.

More than 75 cities have seen protests, with streets only days ago deserted because of coronavirus full of demonstrators marching shoulder to shoulder. Some US officials have warned of protest-connected virus outbreaks.

The Floyd case has reignited deep-seated anger over police killings of black Americans and racism. It follows the high-profile cases of Michael Brown in Ferguson, Eric Garner in New York and others that have driven the Black Lives Matter movement.

For many, the outrage also reflects years of frustration over socio-economic inequality and discrimination, not least in Minneapolis itself, where George Floyd died.

READ ALSO:

Minnesota governor says destruction is no longer about George Floyd and he'll mobilize full National Guard

What's the latest on the protests?

Despite strict curfews and the deployment of the National Guard, many demonstrations that had been peaceful during the day again descended into violence overnight.

Police vehicles were vandalised and set alight in several cities, while riot officers continued to respond with tear gas and flash grenades.

In Philadelphia, local TV stations showed people smashing police cars and looting at least one store.

Mr Trump tweeted: "Law & Order in Philadelphia, NOW! They are looting stores. Call in our great National Guard."

At least 4,400 people have been arrested in several days of protests, according to the Associated Press news agency, for offenses including blocking motorways, looting and breaking curfew.

In Minneapolis, a lorry driver was arrested after reportedly breaching a road barrier before speeding towards a crowd of protesters marching along a major motorway. He has now been charged with assault, CNN reports.

Footage posted on social media showed dozens of people surrounding the vehicle and pulling the driver out from behind the wheel after it came to a stop.

The driver was taken to hospital with minor injuries and later to the county jail. There were no immediate reports of other casualties.

Minnesota's Governor Tim Walz said the motive of the driver was unclear, adding: "To not have tragedy and many deaths is simply an amazing thing."

Many videos shared on social media appeared to show riot police responding disproportionately to demonstrators. In Atlanta, Georgia, two officers were sacked on Sunday for using excessive force - including using a taser on two young college students.

Dozens of journalists have also spoken out about being targeted by police despite making clear they are with the media. A BBC cameraman was charged at by a shield-carrying officer near the White House.

There have also been protests in European cities, including London, Berlin, Zurich, and Brussels.

BBC