Portland police blocked and advanced on demonstrators they said were throwing missiles during unrest in the north of the city that has been riven by protests for more than two months.
On Friday night, protesters had blocked off traffic on North Ainsworth Street, prompting police to instruct them to leave immediately or face arrest, Portland Police said in a statement.
After they found out that around 400 people would be heading to the Portland Police Association building, which had been the scene of previous violent demonstrations, officers positioned themselves to block the marchers.
Officers said that protesters threw paint balls and projectiles and unlawful assembly was declared.
Portland police tweeted: “Failure to adhere to this order may subject you to arrest, citation, and/or the use of crowd control agents, including, but not limited to tear gas and/or impact weapons. Disperse immediately.”
Officers started dispersing the crowd at around 10.20 p.m., an hour after the march had started and a pitched battle ensued with police saying that protesters threw fireworks, golf balls, pieces of concrete and glass bottles.
Jonathan Taylor, of Vancouver, told The Oregonian that as he drove his motorcycle on a ride through town, an officer threw a smoke canister and pointed a gun at him, after he hit his horn and asked if he could go through a blocked street.
By the time the protesters had dispersed, at around 3.45 a.m, four people had been arrested.
The police actions sparked criticism from Portland commissioner Jo Ann Hardesty who tweeted: “This brutality is unacceptable. This is the community the police are sworn to protect and serve. They must uphold Portlanders’ Constitutional rights.”
Oregon’s biggest city has been the scene of nightly demonstrations following the killing of George Floyd in Minneapolis by a police officer in May.
The Associated Press reported that earlier this week, protesters had lit a fire and set off fireworks outside the downtown federal courthouse, the location of a number of violent altercations over the last few weeks between demonstrators and federal agents.
The size of the protests has decreased since Oregon Governor Gov. Kate Brown agreed with Vice President Mike Pence to remove federal officers, who have been replaced by Oregon State Police. However after state police said they would be pulling back, federal officers may return to the city, The Oregonian reported.