Protesters — as they have often in the last seven weeks — rallied around the federal courthouse and county justice center in downtown Portland Friday night and early Saturday.
The protest started with about 200 people blocking traffic outside the county justice center. But some took metal fencing from nearby parks and used them to barricade exterior doors of the justice center and a federal courthouse, Portland police said.
Around 1:30 a.m., city police declared an unlawful assembly and told demonstrators to leave, police said.
Police said they moved in to disperse the crowd and arrested several people who didn’t leave. Officers faced “projectiles such as glass bottles, rocks and broken pieces of metal from fencing,” police said.
By 2:10 a.m., several hundred people returned to the area, and Portland police again dispersed them, arresting several more, authorities said.
Police said they confiscated weapons and shields from some demonstrators. Police released a photo showing some of the items — what appeared to be swords and chest armor.
Portland police said they did not use tear gas.
Oregon’s governor and Portland’s mayor have demanded that the federal officers be withdrawn.
US Customs and Border Protection has said it was one of the agencies involved in arresting protesters.
“Violent anarchists have organized events in Portland over the last several weeks with willful intent to damage and destroy federal property, as well as, injure federal officers and agents,” the agency said in a statement to CNN. “These criminal actions will not be tolerated.”
CNN’s Josh Campbell, Amir Vera and Konstantin Toropin contributed to this report.