Washington, Aug 27 (IANS): Seven US Capitol police officers have filed a civil rights lawsuit against former President Donald Trump and his ally Roger Stone, as well as a number of members of right-wing extremist groups over the deadly January 6 riot.

Filed in a Washington, D.C. federal court on Thursday, the officers accused Trump of acting in concert with right-wing extremist groups like the Proud Boys and Oath Keepers engaged in acts of domestic terrorism during the riot, Xinhua news agency reported.

They alleged that Trump and the other defendants violated both state law and provisions of the Ku Klux Klan Act, an 1871 federal statute that makes it illegal to use force or threats to prevent federal officers from carrying out their official duties.

The plaintiffs, five of whom are African-Americans, claimed that the defendants' move was fuelled by their promotion of white supremacist-laden conspiracy theories and lies about the election being swayed by widespread voter fraud, particularly in areas with significant Black populations.

"The January 6 insurrection was a blatant attempt to stifle the votes and voices of millions of Americans, particularly Black voters," said Damon Hewitt, president of the Lawyers' Committee for Civil Rights Under Law, which is representing the officers.

The complaint is thought to be the first to accuse Trump of conspiring with far-right groups to use "force, intimidation and threats" to block Congress from certifying Joe Biden's presidential election.

The lawsuit came amid an ongoing investigation led by a House select committee into the riot, during which a mob of Trump's supporters breached the Capitol Complex.