US authorities have released a videotape of police shooting an unarmed black man dead in El Cajon, California.
The tape, shot by a surveillance camera at the drive-through window of a taco stand where the incident took place, shows two officers confronting Ugandan-born Alfred Olango, 38, on Tuesday afternoon before one of them opens fire on him.
Family members and activists had called for police to release the video, believing it would show that officers acted improperly during the confrontation with Olango.
Olango's mother, during an emotional press conference on Thursday, said that her son was having a mental breakdown when he was confronted by police at Los Ponchos taco shop in the San Diego suburb and that they should have helped him instead of quickly opening fire.
The tragedy has gained attention in Africa, where officials from several countries criticised Olango's death and the succession of police killings of black men in the United States.
On Thursday night, some 75 protesters gathered near the scene of the shooting and threw rocks and bottles, stopped vehicles and broke car windows, according to the El Cajon Police Department.
Police used pepper spray to disperse the crowd and arrested two men for unlawful assembly, a police statement said.
Attorneys for Olango's family had criticised authorities for previously releasing a photograph of Olango pointing an object at an officer, saying it gave an unfair impression of the former Ugandan refugee, and called for the public release of the full video taken by a bystander.
El Cajon officer Richard Gonsalves and a colleague on the police force, whose name was not released, were responding to emergency calls about a "mentally unstable" man walking in traffic, officials said.
Police have said Olango ignored commands to take his hand out of his pocket before pulling out an object later determined to be a vaping device used to inhale nicotine. Olango assumed a "shooting stance" and pointed the object, which had a 3-inch-long (8-cm) cylinder, police said. No gun was found.
Gonsalves opened fire and the other officer discharged a Taser device, police said. Police have not said how many shots were fired. A family spokesman said Olango was shot five times.
The officers have been placed on administrative leave during an investigation into the shooting.