The governor of the US state of Louisiana has announced the opening of a federal civil rights investigation after the police shooting of a black man in Baton Rouge triggered protests.
"The lead agency conducting the investigation in this matter will be the United States Department of Justice civil rights division, assisted by the Louisiana US Attorney's office and the FBI," Governor John Bel Edwards told a news conference.
Louisiana police shot and killed the man, identified as 37-year-old Alton Sterling, who had been selling CDs outside a shop.
A video shot by a witness and circulated online showed two police officers ordering a tall black man to the ground.
As the man remained standing, the officers wrestled him onto the roof of a car and then to the ground. While he was pinned down by the officers, one pulled a gun and shot him four times at close range.
Both officers appeared to be white.
Police in the state's capital Baton Rouge said two officers "made contact" with Mr Sterling in the car park of the shop.
The shooting took place yesterday at 12.35am local time (5.35am Irish time) after police received a tip from an anonymous caller who said they had been threatened by a man with a gun, according to a police statement.
"An altercation between Sterling and the officers ensued. Sterling was shot during the altercation and died at the scene," police said on Facebook.
They said that in accordance with "standard procedure," the two officers involved in the shooting had been placed on administrative leave during the ongoing investigation.
About 100 people, including friends of relatives of Mr Sterling, protested outside the shop after the incident overnight, some blocking roads, The Advocate newspaper reported.
Holding up handmade signs, they chanted: "Black lives matter" and "Hands up, don't shoot."
"Justice for Alton" and "Justice 4 CD Man" read some of the signs.
Cedric Richmond, a Democratic congressman who represents a Louisiana district that includes most of New Orleans, called for the US Justice Department to conduct a "full and transparent" investigation into the incident.
The video footage of the shooting, he said, was "deeply troubling."
"There are a number of unanswered questions surrounding Mr Sterling's death, including questions about the initial calls for police presence, the level of force used by officers, the verbal and physical altercation and the response of the officers after he was shot," he said in a statement.
Triple S store owner Abdullah Muflahi told The Advocate that he witnessed police retrieving a gun from Mr Sterling's pocket after the shooting, though Mr Sterling did not hold a weapon during the altercation.
"They were really aggressive with him from the start," Mr Muflahi said about the police officers, adding that they were "freaking out" after the incident.
Mr Muflahi said he heard one of the officers say: "Just leave him."
Civil rights group Black Lives Matter, which was referenced by many protesters in Louisiana, tweeted: "Enough is enough. #AltonSterling."
