An unarmed black man has been shot in the back seven times by a police officer.
Jacob Blake, 29, has been hospitalised in a serious condition in the city of Kenosha, Wisconsin.
The shooting happened around 5pm local time as officers responded to a “domestic incident”.
In disturbing footage circulating on social media, two police officers direct Mr Blake towards an SUV.
One of them then shoots him in the back after he opens the door.
Mr Blake’s children were reportedly inside the vehicle and watched as their dad was fired on.
He was trying to break up a fight between two women before being tasered, the Kenosha News reports.
Crowds afterwards gathered at the scene and threw bricks and Molotov cocktails at police, according to social media reports.
Wisconsin Governor Tony Evers tweeted: “We stand against excessive use of force and immediate escalation when engaging with Black Wisconsinites.”
Hundreds of protesters gathered outside a Kenosha police station chanting “Black Lives Matter”.
Demonstrators set fire to vehicles and smashed police cruiser windows, as cops set off tear gas canisters.
The county has since declared a state of emergency and enforced a curfew until 7am local time.
The Wisconsin Department of Justice’s Division of Criminal Investigation said confirmed that the officers have been placed on administrative leave.
Civil rights attorney Benjamin Crump shared the footage of the shooting on Twitter and wrote: “They saw a cop shoot their father.
“They will be traumatized forever. We cannot let officers violate their duty to PROTECT us. Our kids deserve better!!”
Crump is representing the family of George Floyd, who died after being arrested by police outside a shop in Minneapolis, Minnesota, the US, on May 25.
A white police officer, Derek Chauvin, kneeled on Mr Floyd’s neck while he was pinned to the floor and has since been charged with murder.
Three other cops have been charged with aiding and abetting murder.