PORTLAND (REUTERS) - Police shot and killed a self-declared anti-fascist activist in Washington state on Thursday (Sept 3) night as they moved in to arrest him on suspicion he fatally shot a right-wing counterprotester last weekend in Portland, Oregon, officials said.

Michael Reinoehl, 48, wanted on a murder charge, was armed with a semi-automatic handgun when members of a US Marshals Service fugitive task force shot him dead outside an apartment complex in suburban Olympia, Washington, according to the Marshals Service and the Thurston County Sheriff's Office.

His sister, who asked not to be named, said her "estranged" brother believed the United States "was going to war".

"He believed the war was here, and look at where that got him; where it got us," she told Reuters in a text message.

"Two men are dead. He is one of them. Two families have been thrown into chaos, and everyone seems more up in arms than ever. I believe in something different. I believe the peaceful majority are stronger than that."

Reinoehl was in a car when police opened fire, leading him to flee on foot as four officers shot at him, Thurston County Sheriff's Office spokesman Ray Brady told reporters.

Mr Brady could not confirm whether Reinoehl fired on police, but witnesses told reporters a hail of bullets put out car windows and hit nearby homes.

Flowers were placed under the mailbox where Reinoehl fell and where an agent attempted CPR on him before he was pronounced dead at the scene, according to bystander videos.

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

Reinoehl, who provided security for Black Lives Matter in Portland protests, in a video interview with Vice aired hours before his death appeared to admit to shooting Mr Danielson and said the shot "felt like the beginning of a war". He said he acted in self-defence.

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

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

Mr Danielson's friend Michael Hamilton saw no justice in Reinoehl's death and said he and his family were getting death threats and being called "Nazis" after he started a GoFundMe page for Danielson.

"Now they want me to live in fear? Not likely," said Mr Hamilton. "I also refuse to kill my brothers and sisters. If they want civil war they will have to murder me like a dog in the streets like they did my friend, a good and decent man."

ANTIFA

Mr Danielson and Reinoehl were pitted against one another in escalating confrontations between right- and left-wing groups in Portland.

The city has become a focus of the presidential campaign after its nearly 100 days of protests since Mr George Floyd, a black man, died in police custody in Minneapolis on May 25.

Mr Trump, who has made law and order the main theme of his reelection bid, singled out Portland as one of several Democrat-run cities he calls "anarchist jurisdictions". The US Justice Department on Friday directly linked Reinoehl to the left-wing antifa movement, the first time it had done so for a demonstrator facing federal charges in Portland.

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

"Antifa groups murdered my friend," said Patriot Prayer leader Joey Gibson, who on Tuesday called on supporters not to seek revenge.

Facebook Inc on Friday said it took down the pages of Patriot Prayer and Mr Gibson, saying it was part of their efforts to remove "violent social militias" from the platform.

Mr Gibson said Facebook should ban antifa pages, too.

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

"Every Revolution needs people that are willing and ready to fight," he said in a June 16 Instagram post. "It will be a war and like all wars there will be casualties."