Four Minneapolis police officers were fired after a disturbing video circulated online showing an unarmed black man pinned down by an officer kneeling on his neck.
Officials said the man later died at the hospital.
A video of the Monday evening incident 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 relieved the officers involved, called the incident heinous and demanded justice.
"We treat animals better than we treat black lives in this country, and at times in the state of Minnesota... we are also calling on [Hennepin County] Attorney Mike Freeman to charge those officers for their involvement in killing Mr. Floyd."
The FBI of Investigation is investigating the death.
Police officers responded to a call at 8 p.m. local time about a forgery in progress. The officers found the suspect, Floyd, aged in his 40s, in a car.
After he exited the car, a physical altercation between the officers and Floyd ensued. When they handcuffed him, Floyd appeared to be in medical distress, and later died.
No weapons were involved and no officers were hurt in the incident, according to police.
A series of police-involved shootings and killings of black men in recent years have triggered mass protests across the country and led to the formation of the Black Lives Matter movement, which has demanded an end to an unjustified use of lethal force in minority communities.