Protesters have clashed with police in cities across the US over the killing of an unarmed African-American man at the hands of officers in Minneapolis, BBC News reported.

Hundreds of people rallied outside the White House, which was briefly put under lockdown on Friday, demanding justice over the death of George Floyd.

Minnesota, New York, Atlanta and other regions have seen violent unrest.

A former Minneapolis police officer has been arrested and charged with murder over Floyd's death in custody.

Derek Chauvin, who is white, was shown in footage kneeling on 46-year-old Floyd's neck on Monday. He and three other officers have since been sacked.

Chauvin, 44, is due to appear in court in Minneapolis for the first time on Monday.