The unrest stemmed from the weeks of protests over racial injustice and the police treatment of people of colour that flared up after the May 25 death of George Floyd in Minneapolis.
In Portland, thousands of people gathered on Saturday evening for another night of protests over George Floyd’s killing and the presence of federal agents recently sent to the city by President Donald Trump.
Protesters breached a fence surrounding the city’s federal courthouse building where the agents have been stationed.
Police declared the situation to be a riot and at around 1.20am began ordering people to leave the area surrounding the courthouse or risk arrest, saying on Twitter that the violence had created “a grave risk” to the public.
About 20 minutes later, federal officers and local police could be seen attempting to clear the area and deploying tear gas, however protesters remained – forming lines across intersections and holding makeshift shields as police patrolled and closed blocks abutting the area.
Multiple arrests were made, but it was not immediately clear how many.
In Seattle, police officers retreated into a precinct station early on Sunday, hours after large demonstrations in the city’s Capitol Hill neighbourhood.
Some demonstrators lingered after officers filed into the department’s East Precinct at around 1am, but most cleared out a short time later, according to video posted online.
Rocks, bottles, fireworks and mortars were fired at police during the weekend unrest, and police said they arrested at least 45 people for assaults on officers, obstruction and failure to disperse.
Twenty-one officers were hurt, with most of their injuries considered minor, police said.
Meanwhile protesters in Oakland, California set fire to a courthouse, damaged a police station, broke windows, spray-painted graffiti, shot fireworks and pointed lasers at officers after a peaceful demonstration on Saturday evening turned to unrest, police said.
A protest against police violence in Austin, Texas, turned deadly when police said 28-year-old protester Garrett Foster was shot and killed by a person who drove through a crowd of marchers.
Austin Police Chief Brian Manley said a car turned onto the block where protesters stood and honked its horn.
The driver and several witnesses told police that Foster approached the driver and pointed an assault rifle at them.
In video streamed live on Facebook, a car can be heard honking before several shots ring out and protesters start screaming and scattering for cover.
Police could then be seen tending to someone lying in the street.
Mr Manley said the driver called 911 to report the incident and was later taken into custody and released.
Police did not immediately identify the driver.
Sheila Foster, Garrett’s mother, said she was told her son was pushing his fiancee, who uses a wheelchair, through an intersection when the suspect was driving “erratically” through the crowd.
She said she was told the driver shot her son three times.
In the Denver suburb of Aurora, Colorado, meanwhile, a protester shot and wounded someone after a car drove through a crowd marching on an interstate highway, police said.
The wounded person was taken to a hospital in stable condition.
Police did not release many details about the shooting, including whether the person who was shot had been in the car.
