US Police protests
A 35-year-old African immigrant was shot dead by a police officer on June 13, 2015 in Louisville, Kentucky which has led to questions being raised on excessive use of police force. In this photo, protesters hold a sign aloft in front of City Hall during demonstrations in Baltimore, Maryland on May 1, 2015. Reuters/Lucas Jackson

The use of deadly force was justified in the death of an African immigrant on Saturday in Louisville, Kentucky, Metro Police Chief Steve Conrad reportedly said on Sunday, at a news conference. The 35-year-old was shot dead by a white police officer, yet again triggering protests over the role race plays in the country's law enforcement process.

Community activists gathered on Sunday to protest the killing and question why the officer in question -- identified as Nathan Blanford -- did not use a Taser gun or pepper spray to control the incident. A surveillance video reportedly shows that the man, an African immigrant, was shot twice by Blanford, who was responding to a 911 call of assault.

"The officer believed his life was being threatened," Conrad said at the conference, according to NBC News, adding: "Looking at the video," Blanford "didn't have the opportunity to transition" to a "less lethal option."

The video reportedly shows the man approach a woman, grab her purse and cell phone, and throw it on the street. He is also seen punching the woman. Blanford then pulls up at the intersection, following which a brief argument ensues between him and the man, before the latter walks away.

However, he comes back "essentially sprinting toward our officer," swinging a seven- to eight-foot flagpole "in a sledgehammer-like motion," Conrad said, according to NBC News.

The coroner’s office identified the man killed as Deng Manyoun, according to the Associated Press (AP). While witnesses reportedly claimed that Blanford approached the man aggressively, surveillance footage showed the officer standing still and drawing the gun only when the tip of the flag pole is seen emerging from the corner of the video. It was not clear if the pole hit Blanford but he was reportedly taken to a nearby hospital to be treated for injuries.

Manyoun did not speak English and neighbors have speculated that his communication problems may have led to the shooting. Manyoun, who looks unsteady on his feet in the video, had been arrested several times for alcohol-related offenses since 2008, AP reported, citing WHAS TV.

Chanelle Helm, a board member of the Kentucky Alliance Against Racist and Political Oppression, reportedly arranged for a gathering of about two dozen people, who questioned the shooting and chanted, “Black Lives Matter.”

"You're telling me you can't defeat a person with a flagpole who seems to be intoxicated?" Helm said, according to USA Today, adding: "An officer is supposed to be trained to protect people. He lost all type of control.

"The officer went first to kill a man with his gun," Helm said, adding: "He did not subdue him."

Conrad said that Blanford, who has reportedly been on the force since 2005, has been placed on administrative leave while the department's Public Integrity Unit investigates the incident. The inquiry report is expected to be submitted to the Commonwealth Attorney for review.

"I think the officer felt like he was in danger of being killed or suffering serious physical injury, which would allow him under the law and under our policies to go to that option," Conrad said, according to AP. "The last thing any officer wants to do is to take a life," Conrad added.

Last month, the Washington Post reported that police in the U.S. have killed 385 people so far this year.