The Portland Police Bureau declared a civil disturbance and closed part of downtown, it said, after some protesters lit a fire, looted a store and injured an officer with a large rock.
Vigilantes may have instigated violence that led to a shooting in New Mexico, according to officials.
In Tennessee, troopers detained 21 protesters who refused to vacate Capitol grounds.
A man was shot during a protest in Albuquerque’s Old Town Monday night, according to the Albuquerque Police Department.
The victim was transported to the University of New Mexico Hospital and is critical but stable condition, authorities said.
The police chief said he believes that vigilante groups might have been used to instigate violence.
“We are receiving reports about vigilante groups possibly instigating this violence. If this is true, we will be holding them accountable to the fullest extent of the law, including federal hate group designation and prosecution,” Albuquerque Police Chief Michael Geier said in a news release.
Albuquerque Mayor Tim Keller said the shooting was a “tragic, outrageous and unacceptable act of violence,” in a tweet.
“Our hearts go out the victim, his family and witnesses whose lives were needlessly threatened tonight,” Keller said.
New Mexico Governor Michelle Lujan-Grisham said that she is monitoring the situation and praying for the victim. She added that she does not approve of anyone who may have instigated the violence.
“There is absolutely no space in New Mexico for any violent would-be ‘militia’ seeking to terrorize New Mexicans; and there is no space for violence of any kind on our streets and in our communities,” the governor said in a statement.
Downtown Portland closed after officer injured
In Portland, police declared a civil disturbance following tense interactions with demonstrators.
“Due to criminal activity, this has now been declared a civil disturbance. Downtown is now closed from SW Naito to Broadway and SW Lincoln to Harvey Milk,” police tweeted. “Please leave to the North — toward Burnside. We are advising crowd to leave now or be subject to arrest or use of force.”
Police also tweeted that fires have been lit and one store was looted.
Protesters were pointing lasers at officers protecting the Justice Center, according to the Multnomah County Sheriff’s Office. They were also throwing projectiles at law enforcement.
“We are advising the crowd to stop shaking the fence and throwing projectiles. We are here to protect the people who work in the Justice Center and the adults in custody who are living inside … Slingshots are launching objects and additional projectiles are being thrown at deputies. Stop throwing items, stop pointing lasers…” the sheriff’s office said.
As a result of the unrest the police have closed downtown and made arrests, a tweet from Portland Police said.
21 detained in Tennessee
The demonstrators were told to leave by 11 p.m. or they would be arrested but refused to leave.
After receiving several warnings, the protesters sat down and locked legs and arms, according to THP.
The highway patrol said 21 protesters were arrested, 19 received citations and two were arrested for public intoxication.
CNN’s Jennifer Henderson and Mitch McCluskey contributed to this report.