PROTESTERS clashed with police in the US city of Minneapolis today, responding to Monday’s killing of a black man in police custody.

Footage of a white police officer kneeling on George Floyd’s neck for eight minutes, ignoring his pleas for help, was captured on video.

Hundreds took to the streets where the 46-year-old was killed displaying banners reading “I can’t breathe,” the words he was repeatedly heard saying.

Demonstrators were met with a wall of riot police who fired tear gas and projectiles at the crowd. 

Those gathered stood defiant in resistance as scuffles broke out.

Windows of the local police station were smashed and a patrol car damaged in the ensuing melee as demonstrators used shopping trolleys to form a barricade at a supermarket.

Anger has re-erupted with Mr Floyd the latest black man to die at the hands of US police officers: previous deaths led to the establishment of the Black Lives Matter group in protest at a lack of prosecutions.

Authorities confirmed that four officers have been sacked and that the FBI and Minnesota’s Bureau of Criminal Apprehension are carrying out investigations into the incident.

Video initially posted on social media showed a white police officer with a black man pinned to the ground next to the back tyre of his patrol car, his knee on the man’s neck.

The man is heard begging: “Please, please, please, I can't breathe. My stomach hurts. My neck hurts. Please, please. I can't breathe.”

Onlookers pleaded with the officer to stop, with one man saying: “You're stopping his breathing right now, you think that's cool?”

The officer refused to move, while a woman is heard saying: “His nose is bleeding. Look at his nose,” as the man falls silent.

There were calls for intervention to check Mr Floyd’s pulse, but the officer’s knee remained on his neck, despite him being unresponsive, for at least eight minutes before an ambulance arrived.

“The man looked already dead before the ambulance even got there. He was clearly trying to tell them he couldn’t breathe and they ignored him,” Darnella Frazier, one of the people who recorded the incident, told NBC News.

Rights lawyer Benjamin Crump said: “This abusive, excessive and inhumane use of force cost the life of a man who was being detained by police for questioning about a non-violent charge.

“We will seek justice for the family of George Floyd as we demand answers from the Minneapolis Police Department.

“How many ‘while black’ deaths will it take until the racial profiling and undervaluing of black lives by police finally ends?”