Dozens of protesters were arrested overnight in Minneapolis, officials have said, as demonstrations took place despite a curfew imposed after a police officer fatally shot a young Black man.
The killing fueled tensions in the US city already on edge because of the George Floyd murder trial.
Several officers suffered minor injuries and there was sporadic looting, law enforcement officials said, confirming around 40 arrests.
Hundreds of protesters gathered in front of the police station in Brooklyn Center, the suburb where Sunday's killing occurred.
Demonstrators carried signs saying "Jail all racist killer cops," "Am I next?" and "No justice, no peace."
Police fired tear gas and flash bangs to disperse the crowd.
It was the second consecutive night of protests after 20-year-old Daunte Wright was shot dead by a policewoman who appeared to confuse her handgun with her taser.
In police body camera video released earlier yesterday, an officer shouts "Taser! Taser! Taser!" but then instead fires a gun at the victim.
"The officer drew their handgun instead of their taser," said Brooklyn Center police chief Tim Gannon.
Mr Gannon said it was his belief that the officer, now on leave pending an investigation, "had the intention to deploy their taser but instead shot Mr Wright with a single bullet".
"This was an accidental discharge that resulted in the tragic death of Mr Wright," Gannon said. "There is nothing I can say to lessen the pain of Mr Wright's family."
Speaking to ABC television, Mr Wright's father Aubrey said: "A mistake? That doesn't even sound right... I can't accept that. I've lost my son. He's never coming back."
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When officers attempt to handcuff Mr Wright, he scuffles with them and gets back in the car. A female police officer shouts, "I'll tase you."
"Holy shit, I shot him," the officer says as Mr Wright, fatally wounded, drives off. He crashed his car a few blocks away.
How the officer mistook her gun for a taser was unclear.
President Joe Biden called the killing "tragic".
"I think we have to wait and see what the investigation shows," he said.
"In the meantime, I want to make it clear again: there is absolutely no justification, none, for looting".
The protests prompted the defense attorney for former officer Derek Chauvin, who is facing murder and manslaughter charges for George Floyd's death, to ask on Monday for the judge presiding over the high-profile case to sequester the jury.
Judge Peter Cahill refused, stating "this is a totally different case".