Authorities are attempting to stem violent protests over police killings after an officer who pressed his knee into a black man’s neck was charged with murder.

Protesters smashed windows at CNN headquarters in Atlanta, torched a police car and struck officers with bottles, while large demonstrations in New York, Houston, Washington DC, and other cities ranged from people peacefully blocking roads to clashing with police.

Police officer Derek Chauvin, 44, was charged with third-degree murder and second-degree manslaughter after the death of George Floyd who begged for air while being arrested on Monday.

Protests have continued following the death of George Floyd
Protests have continued following the death of George Floyd (Julio Cortez/AP)

In Minneapolis, thousands of protesters marched through the city centre as an 8pm curfew ticked past.

“Prosecute the police!” some chanted, and “Say his name: George Floyd!”

There was no violence, but some protesters sprayed graffiti on buildings while elsewhere in the city, officers fired tear gas and rubber bullets to drive back crowds of protesters.

It was not clear if – or how – authorities would enforce the curfew amid questions about how city and state leaders have handled the crisis.

The video of Mr Floyd's death sparked a national outcry
The video of Mr Floyd’s death sparked a national outcry (Stephen M Dowell/AP)

Chauvin, who was fired along with three other officers who were at the scene, faces more than 12 years in prison if convicted of murder.

A lawyer for Mr Floyd’s family welcomed the arrest but said he expected a more serious murder charge and wants the other officers arrested too.

Prosecutor Mike Freeman said more charges were possible, but authorities “felt it appropriate to focus on the most dangerous perpetrator”.

Minneapolis Mayor Jacob Frey said a curfew also will be in place on Saturday, and nearby cities announced similar restrictions.

“I know that whatever hope you feel today is tempered with scepticism and a righteous outrage,” Mr Frey said in a statement.

“Today’s decision from the County Attorney is an essential first step on a longer road toward justice and healing our city.”

A police car burns after protesters marched to the Georgia State Capitol
A police car burns after protesters marched to the Georgia State Capitol (Alyssa Pointer/AP)

Protests nationwide are being fuelled by outrage over Mr Floyd’s death and years of police violence against African Americans.

Demonstrators clashed with officers in New York and blocked traffic in Houston and San Jose, California.

News of the arrest came moments after Minnesota governor Tim Walz acknowledged the “abject failure” in responding to this week’s protests and called for swift justice for the officers.

Demonstrators walk along Pennsylvania Avenue as they protest the death of George Floyd
Demonstrators walk along Pennsylvania Avenue as they protest the death of George Floyd (Evan Vucci/AP)

Meanwhile, US president Donald Trump threatened action, tweeting “when the looting starts, the shooting starts”, which prompted a warning from Twitter for “glorifying violence”.

Mr Trump later said he was referring to shooting that had happened during the protests and said he had spoken to Mr Floyd’s family and “expressed my sorrow”.

The president called video of the arrest “just a horrible thing to witness and to watch. It certainly looked like there was no excuse for it”.