A black man has been shot dead by police in the US state of Minnesota as protests continued over the police killing of a black man in Louisiana.Philando Castile’s girlfriend live-streamed the aftermath, showing him covered in blood with a police officer pointing his gun at him.He was shot as he reached for his driving licence, she said.It follows the death of Alton Sterling, who was shot dead by police during an incident in Baton Rouge on Tuesday.Hundreds of people have protested for two nights over Sterling’s killing.The deaths follow a long line of high-profile incidents involving African-Americans at the hands of the police, igniting a national debate about the lethal use of force.Castile had been stopped in Falcon Heights, a suburb of St Paul, because the car had a broken rear light, the woman, identified in local media reports as Lavish Reynolds, said.Before he was shot, he told the officer that he was licensed to carry a concealed gun and had one in his possession, she said.‘You shot four bullets into him, sir. He was just getting his license and registration, sir,’ Reynolds says in the video.Police said an investigation was under way and the officer involved has been put on leave.Castile, 32, worked as a cafeteria supervisor at a Montessori school.He was a ‘black individual driving in Falcon Heights who was immediately criminally profiled’, his cousin Antonio Johnson told the Star Tribune newspaper.In Baton Rouge, hundreds of people gathered for a second night of protests at the shop where Alton Sterling, 37, was killed on Tuesday.Some demonstrators chanted ‘Black lives matter’ and called for justice.A video emerged on Wednesday that showed the altercation between Sterling and two police officers.It appears to show Sterling being held down and then shot several times, although some shots are heard when the camera moves away from the confrontation.Seconds later, one of the officers is seen removing an object from the man’s trousers as he lies on the ground with blood on his chest.Police have said Sterling was found to be armed. Officers were initially called because of a 911 report of a man brandishing a gun.The was provided to the Daily Beast by the shop owner, Abdullah Muflahi, who said it proves the man was no threat to the officers when he was shot.