Decision comes as federal prosecutors make final arguments against Proud Boys members accused of seditious conspiracy.

Oath Keeper associates Sandra Ruth Parker, Laura Steele, Connie Meggs and William Isaacs were found guilty of obstructing an official proceeding and various other felony and misdemeanour charges on Monday. They face sentences of up to 20 years in prison.

The same jury in Washington, DC, acquitted two other defendants, Michael Greene and Bennie Parker, of the most serious felony charges.

US District Judge Amit Mehta told the jurors to continue deliberation on the two remaining felony counts against the two men. Both were convicted of lesser misdemeanour charges of entering restricted grounds on the Capitol campus, though neither had entered the building itself.

The convictions conclude the third major trial against Oath Keeper members for the events of January 6, 2021. That day saw supporters of then-US President Donald Trump storm the seat of the US Congress in an attempt to disrupt the certification of the 2020 election results, which showed Trump had lost to Democrat Joe Biden.

The founder of the Oath Keepers, Stewart Rhodes, had previously been convicted of seditious conspiracy in November, one of the most substantial victories for federal prosecutors to date.

The charge of seditious conspiracy is rarely used and difficult to prove. Rhodes and his codefendant Kelly Meggs were the first to be successfully convicted of seditious conspiracy in nearly three decades.

On Monday, federal prosecutors also concluded their case against Enrique Tarrio and several members of the far-right group the Proud Boys. The defendants likewise face charges of seditious conspiracy for their role in allegedly plotting to stop the transfer of power.

Tarrio, founder of the Proud Boys, could face a 20-year prison sentence if found guilty.