A white police officer who shot dead a black motorist in Minnesota is to be charged with second degree manslaughter, prosecutors have told US media.

Officer Kim Potter has said she shot Daunte Wright accidentally, having mistakenly drawn her gun instead of her Taser.

Both she and Police Chief Tim Gannon have quit the Brooklyn Center force.

The killing has sparked three nights of clashes between police and protesters.

The death happened in a suburb of Minneapolis, a city already on edge amid the trial of a white ex-police officer accused of murdering African American George Floyd.

On Tuesday night, bottles and other projectiles were thrown at the Brooklyn Center police headquarters and officers responded by firing tear gas, stun grenades and rubber bullets.

Earlier on Tuesday the families of Mr Wright and Mr Floyd came together to demand an end to the killing of unarmed black Americans by police.

"The world is traumatised watching another African-American man being slain," Floyd's brother Philonise Floyd said.

On Monday Police Chief Gannon said the shooting of Mr Wright appeared to be an "accidental discharge" after Mrs Potter mistook her service pistol for a stun gun.