Warning: Distressing video
A disturbing video has emerged of police officers violently pushing a man to the ground and walking away as he lies there bleeding from his head.
The video from Buffalo, New York state, shows a crowd of police officers clearing protesters when the incident takes place.
It comes among revelations that two of the cops charged with aiding and abetting the murder of George Floyd had been on the force for just four days when he was killed.
Alexander Kueng and Thomas Lane were rookies who were barely off probation, according to their lawyer. Derek Chauvin – the officer who had his knee on Mr Floyd's neck – was their training officer.
More than 140 cities in the US and many more across Europe and around the world have seen people take to the streets. In many cities, protests have turned violent with looting and property damage, as well as 13 people killed and more than 10,000 arrested.
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• George Floyd death: All four officers to be charged over killing
Buffalo Police have since released a statement saying one person was injured when he "tripped and fell" during a "skirmish".
They said five people were arrested as officers enforced an 8pm curfew.