Police in the US city of San Diego have released two videos of the fatal shooting of an unarmed black man outside a shopping centre on Tuesday.

The footage shows two officers confronting Alfred Olango before one of them shoots him dead him in a car park the suburb of El Cajon.

The police said the man had been behaving erratically at the time.

But his mother said he was having a mental breakdown and needed help.

The shooting of Mr Olango, a Ugandan refugee, led to violent protests in El Cajon.

Police said they shot the 38-year-old when he pulled an object that turned out to be an e-cigarette from his pocket and pointed it at a police officer.

One of the videos of the incident was recorded by a surveillance camera mounted at the window of a drive-thru restaurant, while another came from the mobile phone of a bystander.

In the second video, which lasts less than 20 seconds, a woman can be heard shouting: "Officer don't shoot him!" before at least four shots ring out and she screams.

El Cajon police chief Jeff Davis said Mr Olango died after one officer fired an electronic stun gun and another officer simultaneously fired his firearm several times.