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. Police vehicles were set on fire and shops were looted in several cities. The Floyd case has reignited anger over police killings of black Americans.