The 100th consecutive night of protests in Portland quickly escalated into a riot Saturday as people hurled "multiple fire bombs, mortars, rocks and other items" at officers, police said.
One of the homemade bombs caught a community member on fire. Medics offered treatment at the scene, and the injured individual was later taken to a hospital by a private vehicle, according to a press release from the Portland Police Bureau.
"This criminal activity presented an extreme danger to life safety for all community members, and prompted a declaration of a riot," the law enforcement agency said in a statement early Sunday.
More than 50 people were arrested overnight, including at least two who were clad in body armor. One individual was armed with a dagger while another had a knife, police said. The names of those arrested and their charges were not immediately released.
Video posted on social media shows what appears to be a Molotov cocktail being thrown into the middle of crowd and exploding into flames on a residential street. One person's legs appears to catch fire as they run away.
The video shows police in riot gear using flash-bang grenades while making loudspeaker announcements, ordering people to disperse the area. Some demonstrators are seen setting off fireworks in the street as police advance.
A sergeant was struck by a commercial-grade firework, which burned through his glove and injured his hand, according to the Portland Police Bureau. Several other law enforcement officers were hit by rocks in the head, arms, shoulders and feet, with only their protective gear preventing serious injury, police said.
Meanwhile, an Oregon State Police vehicle was damaged by rocks, including broken windows and dents.
The Portland Police Bureau said "it was clear that the intent of the crowd was not peaceful protest," as many people were carrying large shields and were dressed in protective gear, including helmets, gas masks and body armor.
The unrest in Oregon's largest city erupted following the May 25 death of George Floyd, an unarmed 46-year-old Black man who died in Minneapolis after a white police officer was filmed kneeling on his neck as three other officers watched.
Protests in cities across the United States and around the world are calling for an end to police brutality and racial injustice.
Many of the recent demonstrations in Portland have ended in arson, vandalism and violence. Hundreds of protesters have been arrested by authorities there since late May, according to The Associated Press.
Twenty-seven people were arrested following a march Friday night, according to police, who accused protesters of throwing rocks at officers and chanting "burn it down" outside the offices of the Portland Police Association.
Last weekend, a pro-Trump supporter was shot to death during dueling demonstrations in downtown Portland.
The suspected gunman was killed during an encounter with authorities Thursday.