Violence has erupted in cities across the United States on the sixth night of protests sparked by the death in police custody of African-American, GEORGE FLOYD.

Curfews have been imposed in nearly 40 cities, but people have largely ignored them, leading to tense stand-offs.

Riot police clashed with protesters in New York, Chicago, Philadelphia and Los Angeles, firing tear gas and pepper bullets to try to disperse the crowds.

The National Guard said that 5,000 of its personnel had been activated in 15 states and Washington DC.