Police have shot and killed a self-declared anti-fascist activist in Washington state as they moved in to arrest him on suspicion he fatally shot a right-wing counter-protester last weekend in Portland, Oregon, officials said.

Michael Reinoehl, 48, wanted on a murder charge, was armed with a handgun on Thursday night (local time) when members of a US Marshals Service fugitive task force shot him dead in Olympia, Washington, after he left an apartment building and got in a car, according to the Marshals Service and the Thurston County Sheriff’s Office.

“During the attempt to apprehend him, shots were fired at the suspect in the vehicle and he fled from the vehicle on foot. Additional shots were fired at the suspect and he was later pronounced deceased at the location,” the Thurston County Sheriff’s Office, which is responsible for investigating the incident, said in a statement.

Tweet from @USMarshalsHQ

A Multnomah County, Oregon court had charged Mr Reinhoel with the murder of Aaron Danielson, and Portland police issued a warrant for his arrest, asking US marshals to locate him.

“It sounded like fireworks, it was that many shots,” bystander Jashon Spencer said in an online video.

Mr Reinoehl, who had provided security for Black Lives Matter protests in Portland, in a video interview with Vice aired hours before his death appeared to admit he shot Mr Danielson on Saturday night.

Mr Danielson, 39, was part of a caravan of supporters of Republican President Donald Trump who rode in pick-up trucks into downtown Portland and clashed with protesters demonstrating against racial injustice and police brutality.

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This marks the first case in which the Justice Department has directly linked a demonstrator in Portland to a far-left political movement.

Earlier this week, the US Attorney’s Office in Oregon confirmed that none of the defendants from those protests facing federal charges had been linked to any particular group or political ideology.

“The tracking down of Reinoehl – a dangerous fugitive, admitted Antifa member, and suspected murderer – is a significant accomplishment in the ongoing effort to restore law and order to Portland and other cities,” US Attorney General William Barr said in a statement.

“The streets of our cities are safer with this violent agitator removed.”

Nationally, Antifa is a largely unstructured, far-left movement whose followers broadly aim to confront those they view as authoritarian or racist.

Mr Danielson, a Portland man who ran a specialty moving company in the city for over 20 years, was a supporter of right-wing Christian conservative group Patriot Prayer.

Facebook on Friday said it took down the pages of Patriot Prayer and group founder Joey Gibson, whose supporters have clashed with anti-fascists in Portland every weekend since mid-August.

“They were removed as part of our ongoing efforts to remove Violent Social Militias from our platform,” Facebook said in a statement.

Portland has seen escalating confrontations between right- and left-wing groups after nearly 100 days of protests since George Floyd, a Black man, died in Minneapolis on May 25 after a white police officer knelt on his neck.

Mr Reinoehl was previously cited for carrying a loaded gun at a July 5 Portland protest, resisting arrest and interfering with police, according to The Oregonian newspaper. The charges were subsequently dropped, the newspaper reported.

In social media posts Mr Reinoehl, a father of two, described himself as a professional snowboarder, an Army veteran and “100% ANTIFA”.

He said he was prepared to fight to change the “course of humanity”.

“It will be a war and like all wars there will be casualties,” he said in a June 16 Instagram post.

-agencies