A black man killed by police in a Charlotte, North Carolina, parking lot had ignored commands to drop a handgun that officers said he was holding, authorities said on Wednesday hours after 16 officers were injured in protests sparked by the shooting.

 

The trouble in Charlotte unfolded as demonstrators in Tulsa, Oklahoma, demanded the arrest of a police officer there who was seen on video shooting to death an unarmed black man who had his hands in clear view at the time.

 

The two deaths were the latest to raise questions of racial bias in U.S. law enforcement and have stoked a national debate on policing ahead of the U.S. presidential election in November.

 

Police shootings in cities such as New York, Baltimore, Chicago and Ferguson, Missouri, have triggered more than two years of largely peaceful street protests punctuated by days of rioting and arson and given rise to the Black Lives Matter civil rights movement.

 

U.S. Democratic nominee Hillary Clinton called for an end to these types of shootings. Her Republican rival, Donald Trump, questioned what the Tulsa officer was thinking in shooting a man he said seemed to pose no imminent threat.

 

Criminal investigations have been opened in both cities after the shootings, and the U.S. Justice Department has started a separate probe into the Oklahoma incident to see if officers' use of force amounted to a civil rights violation.

 

Bracing for the possibility of more unrest Wednesday night, Charlotte Mayor Jennifer Roberts called for calm and dialogue and urged people to have patience with the investigation.

 

The city's police chief, Kerr Putney, said 43-year-old Keith Scott was seen on Tuesday getting into a vehicle holding a handgun. Police surrounded the car, Putney said, and Scott was shot by a black police officer after he exited the car and did not obey orders to drop his weapon.

 

"He stepped out, posing a threat to the officers," Putney told a news conference, adding that police acted heroically in trying to stem the protests that followed.

 

Scott's family said he was reading in his car and was unarmed, but the police chief disputed that.

 

"I can also tell you we did not find a book," Putney said. "We did find a weapon."

 

North Carolina allows for the open carry of handguns, including having a pistol in a vehicle.

 

One protester was arrested and several were injured in demonstrations that blocked an interstate highway. Rioters set fires and stoned police cars, Putney said, and officers used tear gas to disperse the crowd.

 

'SICK AND TIRED'

U.S. Senator Thom Tillis of North Carolina said the protests were embarrassing and caused "utter chaos."

 

"Charlotte is better than this," Tillis said in a statement.

 

On Wednesday, the American Civil Liberties Union of North Carolina said police should release body and dash camera footage from the scene, and black activists and pastors called for an economic boycott of Charlotte.

 

"We're sick and tired of being sick and tired," civil rights activist John Barnett told reporters near where Scott died.

 

Protesters in Oklahoma, meanwhile, have called for the arrest of Tulsa Police Officer Betty Shelby, who is white, for the killing on Friday of Terence Crutcher, 40, whose sport utility vehicle broke down and was blocking a road.

 

Shelby's lawyer has said she feared for her life, believing Crutcher was reaching into his vehicle for a weapon. Lawyers for the Crutcher family released still images from police videos showing the car window was shut and said the use of force was not justified.

 

Two police videos, one taken from a helicopter and one from a patrol car dashcam, show Shelby with her weapon drawn following Crutcher as he walked slowly to his vehicle with his hand in the air. Shelby shoots him as he puts his hands on the vehicle, and he falls to the ground.

 

Speaking in Cleveland, Trump said it appeared Crutcher had been doing what he was supposed to do: "This officer, I don't know what she was thinking. ... Was she scared? Did she choke?"

 

In a tweet on Wednesday, Clinton said: "Keith Lamont Scott. Terence Crutcher. Too many others. This has got to end."