A woman was pinned to the ground by six police officers after she spat towards them during a day of protests between duelling far-right and anti-fascist activists in Portland.

Hundreds of far-right protesters and anti-fascist counter-demonstrators swarmed the Oregon city at the weekend for a widely publicised right-wing rally that attracted the attention of Donald Trump.

In video circulating online, a woman can be seen walking towards police and spitting at them once before she is wrestled to the floor by a group of officers wearing riot gear.

“Police brutality cannot be tolerated on any level," Riley Renn, the woman who filmed the video, told The Independent.

“Many of the people who were counter-protesting were also there to speak out against [the] lack of accountability when it comes to the United States and our massive police presence.”

Charlottesville one year on Show all 15 1 /15 Charlottesville one year on Charlottesville one year on Mary Grace, from Durham, North Carolina, walks through the downtown mall area August 11, 2018 in Charlottesville, Virginia. Charlottesville has been declared in a state of emergency by Virginia Gov. Ralph Northam as the city braces for the one year anniversary of the deadly clash between white supremacist forces and counter protesters over the potential removal of Confederate statues of Robert E. Lee and Jackson. A "Unite the Right" rally featuring some of the same groups is planned for tomorrow in Washington, DC. Getty Charlottesville one year on Chris Jessee (R) hands out placards to people visiting downtown Charlottesville as the city marks the anniversary of last year's 'Unite the Right rally' in Charlottesville, Virginia, USA, 11 August 2018. On 12 August 2017, a bloody clash between white supremacists and counterprotestors in Charlottesville left three people dead and dozens injured Getty Charlottesville one year on A member of the Virginia State Police waits outside the park where a statue of Confederate Gen. Robert E. Lee is located August 11, 2018 in Charlottesville, Virginia. Charlottesville has been declared in a state of emergency by Virginia Gov. Ralph Northam as the city braces for the one year anniversary of a deadly clash between white supremacist forces and counter protesters over the potential removal of Confederate statues of Robert E. Lee and Jackson. A "Unite the Right" rally featuring some of the same groups is planned for tomorrow in Washington, DC Reuters Charlottesville one year on A woman displays a shirt ahead of the one-year anniversary of 2017 Charlottesville "Unite the Right" protests, in Charlottesville, Virginia, U.S., August 10, 2018. Reuters Charlottesville one year on A sign reading "Strength, which was taken down at the request of police officers, hangs by the statue of Civil War Confederate General Robert E. Lee, ahead of the one-year anniversary of 2017 Charlottesville "Unite the Right" protests, in Charlottesville, Virginia, U.S., August 10, 2018. Reuters Charlottesville one year on Law enforcement arrives ahead of the one year anniversary of 2017 Charlottesville "Unite the Right" protests, in Charlottesville, Virginia, U.S., August 10, 2018 Reuters Charlottesville one year on A vendor displays wares on the mall as State Police lock down the downtown area in anticipation of the anniversary of last year's Unite the Right rally in Charlottesville, Va., Saturday, Aug. 11, 2018. The Governor has declared a state of emergency in Charlottesville AP Charlottesville one year on A Police bike patrol takes a break in the downtown area in anticipation of the anniversary of last year's Unite the Right rally in Charlottesville, Va., Saturday, Aug. 11, 2018. State and local authorities framed the weekend's heightened security as a necessary precaution. AP Charlottesville one year on State Police arrest a local resident, John Miska, in the locked down downtown area in Charlottesville, Va., Saturday, Aug. 11, 2018. Miska purchased razor blades, which are banned items, in a downtown drugstore. On the the anniversary of white supremacist violence, state and local authorities framed the weekend's heightened security as a necessary precaution. AP Charlottesville one year on State Police escort local resident, John Miska, red hat, after he was arrested in the locked down downtown area in Charlottesville, Va., Saturday, Aug. 11, 2018. Miska purchased razor blades, which are banned items, in a downtown drugstore. On the the anniversary of white supremacist violence, state and local authorities framed the weekend's heightened security as a necessary precaution. AP Charlottesville one year on A group Anti-fascism demonstrators, march in the downtown area in anticipation of the anniversary of last year's Unite the Right rally in Charlottesville, Va., Saturday, AP Charlottesville one year on A group anti-fascism demonstrators march in the downtown area in anticipation of the anniversary of last year's Unite the Right rally in Charlottesville, Va., AP Charlottesville one year on People receive first-aid after a car accident ran into a crowd of protesters in Charlottesville, VA on August 12, 2017. A vehicle plowed into a crowd of people Saturday at a Virginia rally where violence erupted between white nationalist demonstrators and counter-protesters, witnesses said, causing an unclear number of injuries AFP/Getty Charlottesville one year on Alt-right rally members in Lee Park in Charlottesville, VA on Saturday August 12, 2017 White nationalist 'Unite the Right' rally, Charlottesville, USA Rex Charlottesville one year on A counter protester who got hit with a stick by alt-right member covered with blood on his face in Lee Park in Charlottesville, Rex

It is not clear whether the woman involved was part of an official protest or just a passer-by in the area.

Portland Police told The Independent that the woman in the video has not been charged with a crime at this point.

"As the investigation into the demonstration events continue, detectives and the Multnomah County District Attorney’s office will determine if future charges are appropriate," a spokesperson said.

"All uses of force by Portland Police Officers are reviewed by a supervisor in an After Action report and sent through the chain of command to the Police Inspector’s office."

At least 13 people were arrested in the city on Saturday as officers seized metal poles, bear spray and other weapons during the right-wing rally.

On Saturday, Mr Trump showed support for one of the demands of right-wing demonstrators by saying “major consideration” was being given to naming the anti-fascist group Antifa an “organisation of terror”.

Leaders of right-wing groups have vowed to return to the city so long as Antifa groups remain active in the area.

However, Portland’s mayor Ted Wheeler said Joe Biggs, the organiser of the event, was not welcome in the city.

"We do not want him here in my city. Period,” Mr Wheeler said, adding that he believed the demonstrations were linked to “a rising white nationalist movement” in the US.

"Portland, being a very progressive community, is always going to be at or near ground zero of this battle,” he said.

More than two dozen local, state and federal law enforcement agencies, including the FBI, were in the city for the event, which was attended by members of the far-right Proud Boys group and Three Percenters militia movement.

Lieutenant Tina Jones, a police spokesperson, said there were about 1,200 people on the streets at the peak of the protests.

The Proud Boys, who organised the event on Saturday, have been designated a hate group by the Southern Poverty Law Centre.

The rally was inspired by a viral video of conservative blogger Andy Ngo being attacked by anti-fascist protesters in June.