Police use tear gas to disperse protesters during a demonstration in Minneapolis, Minnesota, on May 29, 2020, over the death of George Floyd, a black man who died after a white policeman kneeled on his neck for several minutes. (Photo by AFP)

Cities across the US have witnessed protests over the killing of an African-American man by US police. George Floyd was choked to death by a white police officer in Minneapolis. His death has sparked anger over racial discriminations in the US.