Capitol police officers who were attacked and beaten during the insurrection at the US Congress on 6 January by extremist supporters of Donald Trump filed a lawsuit on Thursday against the former Republican president, his ally Roger Stone and members of far-right extremist groups.

The officers accused them of intentionally sending a violent mob to disrupt the congressional certification of Joe Biden’s victory in the November 2020 election.

The suit in federal court in Washington DC alleges Trump “worked with white supremacists, violent extremist groups, and campaign supporters to violate the Ku Klux Klan Act, and commit acts of domestic terrorism in an unlawful effort to stay in power”.

The suit was filed on behalf of the seven officers by the Lawyers’ Committee for Civil Rights Under Law.

“Trump’s and his co-conspirators’ repeated cries of election fraud caused many of his supporters, including other defendants, to plan to employ force, intimidation and threats on his behalf to keep him in office, should he lose the election,” the lawsuit alleges.

“Because of defendants’ unlawful actions, plaintiffs were violently assaulted, spat on, teargassed, bear-sprayed, subjected to racial slurs and epithets, and put in fear for their lives. Plaintiffs’ injuries, which defendants caused, persist to this day,” the lawsuit added.

It names the former president, the Trump campaign, Stone and members of the extremist far-right groups the Proud Boys and Oath Keepers, some of whose members were involved at the Capitol attack.

Roger Stone is understood to have links to some of the far-right individuals who have been charged as a result of the riot in Washington DC. Stone was pardoned by Trump just before the then president left office after his defeat, having previously had his prison sentence commuted for crimes in relation to the Russia investigation into the 2016 election campaign.

Trump held a rally near the White House on 6 January in which he encouraged his supporters to march on the nearby Capitol in an effort to stop certification of Biden’s victory over him, which was due to take place in a process involving the House of Representatives and the US Senate that day.

The officers listed in the lawsuit are Conrad Smith, Danny McElroy, Byron Evans, Governor Latson, Melissa Marshall, Michael Fortune and Jason DeRoche. Collectively, the officers “have dedicated more than 150 years” to protecting Congress.

While several police officers who served during the riots have come forward with stories of their experiences on 6 January, most notably during the congressional hearing in July, Thursday’s lawsuit is the first time that the seven plaintiffs, five of whom are Black, offered details of their experiences.

“One attacker shoved Officer Latson … Attackers then breached the Senate Chamber, physically assaulted Officer Latson, and hurled racial slurs at him, including ‘n****r’ … Officer Latson suffered physical injury from being physically struck by attackers and from exposure to noxious pepper spray, bear spray, fire extinguishers, and other pollutants sprayed by attackers,” the lawsuit said.

Another officer, Michael Fortune, upon arrival at the Capitol, “saw that it was like a war zone, with chemical fog in the air, tables flipped, statues defaced, feces on the walls, and blood and broken glass on the floors”.

DeRoche, an 18-year Capitol police veteran and a navy veteran, said the lawsuit was not about a monetary settlement. Rather, he said, the lawsuit aimed to set the record straight about what happened on 6 January. He wanted Trump and the other defendants to be held accountable for their actions, so “if they were to do this ever again, there would be consequences,” the suit said.

A House committee has started in earnest to investigate what happened that day, sending out requests on Wednesday for documents from intelligence, law enforcement and other government agencies.

More than 500 people who took part in the insurrection are facing criminal charges in one of the biggest federal investigations since the September 11, 2001, terrorist attacks on the US.

Two other similar cases have been filed in recent months by Democratic members of Congress. The suits allege the actions of Trump and his allies led to the violent siege of the Capitol that injured dozens of police officers, delayed the certification of Biden’s victory and sent lawmakers running for their lives.

Trump accused the committee of violating “longstanding legal principles of privilege” but his team had no immediate comment on Thursday’s lawsuit.

“Racism and white supremacy pervaded Defendants’ efforts from the outset,” the lawsuit said.

Thursday’s lawsuit was the first to accuse Trump of working with both far-right extremists and political organizers to promote his dishonest allegations of a fraudulent election.

“This is probably the most comprehensive account of 6 January in terms of civil cases,” said Edward Caspar, a lawyer who is leading the lawsuit.