PHOTOS: Minneapolis burns after racially charged police killing of George Floyd

The fatal arrest of an African-American man in the U.S. city of Minnesota has sparked countrywide protests; his death was reminiscent of the 2014 killing in New York City of Eric Garner, who was put in a banned police chokehold and was heard saying, "I can't breathe."

The fatal arrest of a black man who complained of suffocation as a white police officer knelt on his neck plunged the U.S. city of Minneapolis into chaos this week and sparked nationwide protests.

In Minneapolis, furious demonstrators set a police station ablaze on Thursday, the third day of violent protests that have now spread to the Minnesota state capital, St. Paul. Other buildings in the area were also torched. So was a car. A discount store was looted.

Elsewhere in the city, citizens marched peacefully to ask for justice for George Floyd, 46, who died on Monday. Four police officers who were involved in the incident have been dismissed from duty.

There's also worrying news from Louisville, the capital of Kentucky state, where police say seven people were shot during protests demanding justice for Breonna Taylor, a black woman fatally shot by police earlier this year.

U.S. President Donald Trump said he would send National Guard troops and "get the job done right" if Minneapolis's mayor couldn't bring things under control.

"Any difficulty and we will assume control but, when the looting starts, the shooting starts," he tweeted.

The Minnesota National Guard said it had "activated" more than 500 soldiers to assist local authorities, and mainly the fire departments, in Minneapolis, St. Paul and surrounding areas.

The death of George Floyd case was reminiscent of the 2014 killing of Eric Garner, an unarmed black man in New York City who died after being put in a banned police chokehold.

Like Floyd, he, too, was heard to mutter, "I can't breathe."

Eric Garner's dying words became a rallying cry for the Black Lives Matter movement that formed amid a wave of killings of African-Americans by police.

Inputs from agencies