The United Nations High Commissioner for Human Rights, Michelle Bachelet, has sentenced the death of black American George Floyd to a police operation in Minneapolis. Floyd's death was only the latest incident in "a long line of killing" unarmed black Americans by police officers, Bachelet said. 

Authorities in the US must take "serious measures" to prevent such killings and hold the perpetrators accountable, Bachelet said. The role of "deeply rooted and widespread discrimination" of people of different skin colors in such crimes must also be investigated, she continued.

The 46-year-old Floyd had died on Monday after a brutal police operation. Videos of passersby showed how a police officer pressed his knee into the neck of the suspect lying on the ground for minutes - and maintained this position even after the man had apparently lost consciousness.

The case has caused horror in the United States. The four police officers involved in the operation have been released. The federal police FBI is investigating the incident.

In the city in the state of Minnesota there have been repeated protests and serious riots since Tuesday evening.

"I can't breathe," says the demonstrator. George Floyd kept saying that to the cop who was kneeling on his neck.
Protesters gather outside the police station where the four officers worked, who have now been released due to the brutal dealings with Floyd.
Police officers lined up in front of the station to shield the building from the demonstrators.
The police used tear gas and rubber bullets to push the crowd back.
Floyd's portrait hangs on a street lamp.
A man with a pig's head expresses his protest against the police.
Barricades on the street in front of the police station
Loud protest against excessive police violence
The police respond with tear gas.
A protester turns away from the tear gas.
An injured person is lying on the floor.
A man who was injured in the eye is carried away.
The previous evening, thousands of demonstrators protested against police violence in the US city of Minneapolis.
This shop was ransacked on the sidelines of the demonstration.
With a partly burned American flag, this man shows his protest against the state authorities.
A car parts store is set on fire on the sidelines of the protests.