WASHINGTON (AFP) - The mayor of Charlotte, North Carolina appealed for calm on Wednesday (Sept 21) after a night of violent protests and looting sparked by the fatal police shooting of a black man said to have been armed with a handgun.

Police said 16 officers and several demonstrators were injured in clashes after the shooting death of 43-year-old Keith Lamont Scott, the latest in a string of police involved killings that have fueled outrage across the United States.

"We are calling for peace, we are calling for calm, we are calling for dialogue," Charlotte Mayor Jennifer Roberts said.

The shooting occurred at 4pm on Tuesday in the parking lot of an apartment complex in Charlotte after officers arrived in search of a suspect wanted for arrest, police said.

They spotted a man with a handgun - later identified as Scott - exit and then reenter a vehicle, Charlotte-Mecklenburg police chief Kerr Putney told journalists.

Officers approached the man and loudly commanded him to get out and drop the weapon, at which point Scott exited the vehicle armed, according to police.

"He stepped out, posing a threat to the officers, and officer Brentley Vinson subsequently fired his weapon, striking the subject," the police chief said.

Putney added, however, that he did not know that Scott "definitively pointed the weapon specifically towards an officer." Carrying a firearm is legal under local "open carry" gun laws.

Scott's relatives told local media that he was not carrying a gun, but had a book in his hands when he was shot dead, which police disputed.

"I can tell you a weapon was seized. A hand gun," Putney said. "I can also tell you we did not find a book that has been made reference to." Putney said Vinson, who joined the force in 2014, was in plain clothes but wearing a vest carrier emblazoned with the police logo, and was backed up by three officers in full uniform.

He said Vinson was not wearing a body camera, but the other officers were.

"The videos that I've reviewed I cannot see in totality everything that occurred," Putney said.

In Charlotte anger simmered in the aftermath of the night's unrest, especially regarding the police chief's assertion that Scott was armed.

"It's a lie," said Taheshia Williams, whose daughter goes to school with the victim's son.

"They took the book and replaced it with a gun."

Presidential candidates Donald Trump and Hillary Clinton were quick to weigh in on the violence in Charlotte and last Friday's fatal shooting in Tulsa of Terence Crutcher, which was captured on video.

"Keith Lamont Scott. Terence Crutcher. Too many others. This has got to end. -H," tweeted Democrat Clinton, signing the post herself.

After calling to "make America safe again" in a tweet, Trump suggested later Wednesday that the Tulsa officer who shot Crutcher had "choked."

"I don't know what she was thinking," the Republican said, speaking at an African-American church in Cleveland, Ohio.

"Did she get scared? Was she choking? What happened?"

Roberts, Charlotte's mayor, said she was in touch with the White House along with state and local leaders. The city was preparing to handle more potential demonstrations by bolstering its police presence.

The protests swelled on Tuesday evening as news of the shooting spread, with protesters carrying signs that read "Black Lives Matter" and chanting "No justice, no peace!" Putney said the situation turned violent within about two hours with "agitators" damaging police vehicles and throwing rocks at police officers.

Riot control police were called out and used tear gas to disperse the crowd, Putney said.

A group of protesters nevertheless marched to a major highway early Wednesday, shutting down traffic in both directions. They broke into the back of truck and set goods on fire, according to police.

"We all see this as a tragedy," Roberts said. "We all want to work toward a peaceful community. We know that we have work to do."

Scott's death is the latest in a series of fatal police shootings - from Baton Rouge, Louisiana to St Paul, Minnesota - that have left the African American community demanding law enforcement reforms and greater accountability.

The deadly shooting in Tulsa of Crutcher was recorded by police car dashboard cameras and a police helicopter camera, footage the city's police chief Chuck Jordan called disturbing and "very difficult to watch."

In the video, the 40-year-old Crutcher is seen with his hands up, appearing to comply with police officers before he is shot once by officer Betty Shelby, and falls to the ground. Another officer fires his stun gun.

The US Department of Justice said on Monday it would conduct a federal civil rights probe into the Tulsa shooting, an investigation parallel to the one local authorities in the state are carrying out.