MINNEAPOLIS: Protesters clashed with riot police firing tear gas for a second night in Minneapolis on Wednesday in an outpouring of rage over the death of a black man seen in a widely circulated video growing limp and lifeless as a white officer knelt on his neck.

The video, taken by an onlooker to Monday night's fatal encounter between police and George Floyd, 46, showed him lying face down and handcuffed, gasping for air and groaning for help, repeatedly saying, "I can't breathe."

The second day of demonstrations, accompanied by looting, began hours after Mayor Jacob Frey urged prosecutors to file criminal charges against the white policeman shown pinning Floyd to the street.

The policeman and three fellow officers who participated in Floyd's apprehension were dismissed from the police department on Tuesday as the FBI opened an investigation into the incident.

Floyd, reportedly suspected of trying to pass counterfeit bills at a corner eatery, was taken by ambulance from the scene of his arrest and pronounced dead the same night at a hospital.

Hundreds of protesters, many with faces covered, thronged streets around the Third Precinct police station late on Wednesday, about half a mile from where Floyd had been arrested, chanting, "No justice, no peace" and "I can't breathe."

The crowd grew to thousands as night fell and the protest turned into a standoff outside the station, where police in riot gear formed barricade lines while protesters taunted them from behind makeshift barricades of their own.

Police, some taking positions on rooftops, used tear gas, plastic bullets and concussion grenades to keep the crowds at bay, while protesters pelted police with rocks, water bottles and other projectiles. Some threw tear gas canisters back at the officers.

Television news images from a helicopter over the area showed dozens of people looting a Target store, running out with clothing and shopping carts full of merchandise.

Fires erupted after dark at several businesses, including an auto parts store, and eyewitnesses said the blazes appeared to be the work of arsonists. Media said a smaller, peaceful protest was held outside the suburban home of one of the police officers.

On Twitter, President Donald Trump said he had urged the FBI investigation "to be expedited," adding that he appreciated "all the work done by local law enforcement."

"My heart goes out to George's family and friends. Justice will be served!" he said.

"I CAN'T BREATHE"

The video of Monday's deadly confrontation between police and Floyd has stirred a national outcry and led Mayor Frey to call on Wednesday for Hennepin County Attorney Mike Freeman "to charge the arresting officer in this case."

The city identified the four officers as Derek Chauvin, Thomas Lane, Tou Thao and J Alexander Kueng. It did not say who had his knee against Floyd's throat, and gave no further information.

The Police Officers' Federation of Minneapolis, a police union, said in a statement the officers involved were cooperating with investigators and it was "not time to rush to judgment."

"We must review all video. We must wait for the medical examiner's report," the union said, asking the community to remain calm.

Frey did not say what charge was appropriate for the officer, but said he has relayed his wish to Freeman.

On Tuesday, the county attorney's office said it would make a charging decision after state investigators and the FBI conclude their inquiries.

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

Garner's dying words, "I can't breathe," became a rallying cry for the Black Lives Matter movement calling attention to a wave of killings of African-Americans by police using unjustified lethal force.