A man drove into a Seattle crowd protesting the death in police custody of George Floyd before shooting one of the demonstrators on Sunday, police said.
The suspect was detained and the 27-year-old man who was shot in the arm was taken to hospital by firefighters, police said in a tweet. Officials did not name the shooter or the victim.
Police confirmed a gun was recovered and no other people were injured.
Video shared on Twitter by a bystander at the incident showed a man emerging from a vehicle that appeared to have struck a barricade at an intersection. The driver appeared to be carrying a gun in one hand as he ran into the crowd. The sound of what appeared to be gunshots could be heard on video of the incident from the scene.
One witness told NBC News' local affiliate KING that the victim had tried to stop the vehicle from driving into the crowd before the driver shot him. NBC News was not able to confirm this account.
Police later tried to disperse the protesters and said some people had thrown projectiles and fireworks at officers, the department said on Twitter. Police said some demonstrators had shone green lasers in officers' eyes.
Police said they were responding with pepper spray and blast balls. Police also authorized the use of tear gas.
It followed tense demonstrations on Saturday when police used flash bang devices and pepper spray to disperse protesters after rocks, bottles and explosives were thrown at officers.
The mayor and police chief had said they were trying to deescalate tensions.
The protests were among nationwide demonstrations sparked by the death of Floyd, the African American man who was killed on May 25 while in police custody in Minneapolis. Although protesters clashed with police in Seattle, most demonstrations elsewhere in the country over the weekend - including a gathering of thousands at the nation's capital - were peaceful.
The shift in tone followed many demonstrations that took an ugly turn with incidents of arson, assault and looting, leading some cities to impose curfews. At least 10,000 people have been arrested in relation to the protests, according to tracking by the Associated Press.
The Associated Press contributed to this report.