CHARLOTTE — Protesters took to the streets for a third night in the US city of Charlotte on Thursday amid heavy security aimed at preventing more clashes over the fatal police shooting of a black man.

Hundreds marched to the city police station carrying signs saying "Stop killing us" and "Resistance is beautiful," but the atmosphere was far calmer than the previous two nights.

Pressure was growing on police to release video of the shooting of Keith Lamont Scott, a 43-year-old African American, whose killing on Tuesday sparked the unrest.

Scott’s death was the latest in a string of police-involved killings of black men that have fueled outrage across the United States.

North Carolina’s governor has declared a state of emergency in Charlotte, and several hundred National Guard troops and highway police officers were deployed to reinforce local police protecting city infrastructure and businesses.

An overnight curfew was also in place.

"We are going to be a lot more proactive," Charlotte police chief Kerr Putney told a news conference. "We made 44 arrests last night because we are not going to tolerate the behavior."

A protestor shot by a civilian in Wednesday night’s protests died in hospital on Thursday, local media reported.

Shooting video

Scott was shot and killed in an apartment complex parking lot on Tuesday during an encounter with police officers searching for another person wanted for arrest.

Conflicting versions of what happened – police say Scott was armed with a handgun while his family says he was holding a book – fueled the angry protests.

The authorities have so far refused to release police video of the incident.

However, members of Scott’s family watched the footage on Thursday, raising "more questions than answers", their lawyers said.

No gun is visible in the video, which shows Scott stepping backward when he was shot, one of the lawyers told CNN.

"His hands are down by his side. He is acting calm," Justin Bamberg said.

"You do see something in his hand, but it’s impossible to make out from the video what it is."

Putney has said a handgun was recovered at the scene, and that no book was found, contrary to the family’s assertion.

The video footage "does not give me absolute definitive visual evidence that would confirm that a person is pointing a gun," he told CNN.

But the footage indicates the officer identified as having shot Scott – Brentley Vinson, who is also black – was justified, he added.

"The officer perceived his failure to comply with commands, failure to drop the weapon and facing the officers as an imminent threat," he told Fox News on Thursday.

Protesters ’seething’

A handful of protesters confronted police on Thursday night. However, many marched past officers who posed a less intimidating presence on the streets despite their greater numbers.

"Black lives don’t matter in this country," said a 34-year-old protester with a mask around his neck who identified himself only as "Amen-Ra".

"We’re coming together to make them matter, to force America to make them matter – either through violence or peacefully."

Scott’s shooting came on the heels of another fatal police shooting of a black man, Terence Crutcher, in Tulsa, Oklahoma on Friday.

Tulsa authorities charged the police officer who killed Crutcher with first-degree manslaughter on Thursday.

The troubles in Charlotte reverberated on the US presidential campaign trail, with Republican candidate Donald Trump suggesting that drug use in the inner city was somehow responsible.

"And if you’re not aware, drugs are a very, very big factor in what you’re watching on television at night," he said during a speech in Pittsburgh.

Democrat Hillary Clinton discussed the unrest in calls to the Charlotte mayor and US Congresswoman Alma Adams Thursday, her campaign said.

"Too many black Americans have lost their lives and too many feel that their lives are disposable," the campaign cited her as saying. — AFP