A police chief has been sacked after an African American restaurateur was fatally shot in the US during protests over the killing of George Floyd.

Police and National Guard troops fired weapons to disperse a crowd on Monday night in Louisville, Kentucky, protesting against the police killings of African Americans.

David McAtee, 53, died during the incident on Monday night though the specifics of what happened have yet to be confirmed. 

The chief of police in Louisville Steve Conrad was sacked and two officers placed on administrative leave after authorities learned the officers had fired their weapons without using body cameras to record what happened, Mayor Greg Fischer said.

"We had a horrible tragedy last night at 26th and Broadway," Fischer said. "We lost a wonderful citizen named David McAtee."

Louisville Metro Police Chief Steve Conrad was relieved of duty by Mayor Greg Fischer on Monday (
Image:
Kentucky Law Enforcement Council)

Mr McAtee's mum described him as a "community pillar," USA Today reports.

"He left a great legend behind," she said. "He was a good person. Everybody around him would say that.

"My son didn't hurt nobody. He didn't do nothing to nobody."

The death of Mr McAtee, who owned YaYa's BBQ near the site of the shooting, marked the second time Louisville police did not use their body cameras during a shooting incident in which an unarmed black resident was killed.

Louisville Metro Police officers don protective masks during a protest against the deaths of Breonna Taylor and George Floyd (
Image:
REUTERS)
Protesters and police stand off as tear gas is deployed in the streets on Saturday night (
Image:
Getty Images)

Like protesters across the country, the Louisville marchers were incensed by the treatment of Mr Floyd, a 46-year-old black man who died in Minneapolis police custody after being pinned beneath a white officer's knee for nearly nine minutes.

But they were also protesting against the Louisville officers who shot 26-year-old Breonna Taylor while serving a "no knock" search warrant at her apartment.

Protests over racial inequality have engulfed the nation's major cities for a week, as officials extended curfews in hopes of preventing a seventh night of looting and vandalism over the death of Floyd.

Mr Fischer said authorities know two Louisville police officers and two National Guard soldiers had fired their weapons during the incident in which Mr McAtee died.

The officers claim they returned fire after someone shot at them, Mr Fischer added.

Kentucky Governor Andy Bashear promised an exhaustive investigation.

"My pledge is that we will give you the truth, no matter what the truth is," he told a news conference.