Thousands of protesters gathered outside the federal courthouse in Portland into the early hours of Saturday, directing fireworks at the building as plumes of tear gas dispensed by US agents lingered above.
The demonstration went on for hours until federal agents entered the crowd at around 2.30am and marched in a line down the street, clearing remaining protesters with tear gas at close range. They also extinguished a large fire in the street outside the courthouse.
The Federal Protective Service had declared the gathering as “an unlawful assembly” and cited that officers had been injured.
As the crowd dispersed, someone was found stabbed nearby, Portland police said. The person was taken to a hospital and a suspect was detained.
Earlier, the protest had drawn various organised groups, including Healthcare Workers Protest, Teachers against Tyrants, Lawyers for Black Lives and the “Wall of Moms”.
As the crowd grew – authorities estimate there were 3,000 present at the peak of the protest – people were heard chanting “Black Lives Matter” and “Feds go home” to the sound of drums.
Later, protesters vigorously shook the fence surrounding the courthouse, shot fireworks towards the building and threw glass bottles. On many occasions, such actions were met by federal agents using tear gas and flash bangs.
The flow of tear gas caused protesters to disperse at times, but some came armed with leaf blowers and directed the gas back to the courthouse.
Friday’s protest came hours after a US judge denied the state of Oregon’s request to restrict federal agents’ actions in the city.
Democratic leaders in Oregon say federal intervention has worsened the two-month crisis, and the state attorney general sued to allege some people had been whisked off the streets in unmarked vehicles.
US District Judge Michael Mosman said the state lacked standing to sue on behalf of protesters because the legal action was a “highly unusual one with a particular set of rules”.
The clashes in Portland have further inflamed the nation’s political tensions and triggered a crisis over the limits of federal power as Mr Trump moves to send US officers to other Democratic-led cities to combat crime.
The legal action from Oregon Attorney General Ellen Rosenblum accused federal agents of arresting protesters without probable cause and using excessive force. She sought a temporary restraining order to “immediately stop federal authorities from unlawfully detaining Oregonians”.
Ms Rosenblum said the ramifications of the ruling were “extremely troubling”.
She added: “While I respect Judge Mosman, I would ask this question: If the state of Oregon does not have standing to prevent this unconstitutional conduct by unidentified federal agents running roughshod over her citizens, who does?”