Police in Corvallis are investigating a large fight that broke out downtown Monday that involved multiple people, including well known neo-Nazi activist James Marr.

An associate of Marr's, Andrew Oswalt, is currently serving a 40-day sentence in the nearby Benton County Jail on a felony hate crime charge, first degree intimidation, and a misdemeanor criminal mischief charge.

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Police say they’re not sure what started the fight. They’re still looking for witnesses and security camera footage that might have captured it.

"Clearly people know Mr. Marr around the valley," said Lt. Daniel Duncan, spokesman for the Corvallis Police Department. "To what degree that played in to the altercation with these people, that’s something we’re investigating."

Related: Hateful But Not A Hate Crime

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According to the Anti-Defamation League, Marr uses his truck to display numerous provocative anti-Semitic messages.

Marr's white supremacist activism included an attempt to take control of the city of Leith, North Dakota to create a home for whites, according to the Anti-Defamation League.

On Monday, Marr had parked his truck, painted with a swastika and a pro-Nazi message, near the Benton County courthouse, and later moved it to the block where the fight broke out, according to the Corvallis Gazette Times.

Police responded to a 911 call about the fight. When they arrived, Marr was suffering from a medical emergency and they took him to a hospital. It isn't clear if the fight had caused Marr's medical problem, according to Duncan.

Police arrested four men and charged them with disorderly conduct for their roles in the fight. Lt. Duncan says police could bring more charges as the investigation continues.

Meanwhile, anti-fascist groups in Oregon are circulating an online fundraiser for "the Corvallis anti-fascist community who may have been injured or arrested on December 17, 2018."

The Corvallis Police Department says it doesn’t know whether the four people it arrested are members of Antifa.

The fundraiser is using the name Corvallis Community Defense Fund. Contact information for the organizer was not available and posts do not indicate if the organizer has a relationship with the people arrested in the incident Monday.