WATCH | 'I can't breath': Four Minnesota cops fired after death of unarmed George Floyd

Four Minneapolis police officers were fired on Tuesday, a day after a bystander's cellphone video captured one of them kneeling on the neck of an unarmed black man who later died in a hospital.

A video of the incident on Monday evening showed an officer pressing his knee into the neck of the man who was later identified as George Floyd.

Racial Justice Network's Nekima Levy-Armstrong, who said she was glad that the police chief fired the officers involved, called the incident heinous and demanded justice.

Hours after the officers' dismissals were announced, thousands of protesters filled the streets. The event was organised by a number of local activist groups, including the Minneapolis NAACP, Communities Against Police Brutality, and Black Lives Matter Twin Cities.

A series of police-involved shootings and killings of black men in recent years has triggered mass protests across the US and led to the formation of the Black Lives Matter movement, which has demanded an end to the unjustified use of lethal force in minority communities.

The FBI is investigating the death.