Washington (AFP) - The founder of the far-right group Oath Keepers and 10 others were indicted for seditious conspiracy in the January 6, 2021 assault on the US Capitol, the Justice Department announced Thursday.

It was the first use of the potent sedition charge in the sprawling investigation of the Capitol attack by supporters of then-president Donald Trump.

Stewart Rhodes, 56, who founded and led the right-wing militia group, and another associate of the organization, Ed Vallejo, were arrested early Thursday.

Nine men with ties to the Oath Keepers who had been previously arrested on lesser charges in the violent attack, which temporarily shut down the US Congress, were also named as part of the alleged seditious conspiracy.

"Following the Nov. 3, 2020, presidential election, Rhodes conspired with his co-defendants and others to oppose by force the execution of the laws governing the transfer of presidential power by Jan. 20, 2021," the Justice Department said in a statement.

It said that beginning in December 2020, they secretly made plans to travel to Washington, to prevent certification of Joe Biden's victory over Trump in the presidential election.

They brought weapons to Washington as part of their plans for "breaching and attempting to take control of the Capitol grounds and building," it said.

"While certain Oath Keepers members and affiliates breached the Capitol grounds and building, others remained stationed just outside of the city in quick reaction force (QRF) teams... prepared to rapidly transport firearms and other weapons into Washington" to halt the certification, the department said.

If found guilty, they face up to 20 years in prison on the conspiracy to sedition charge alone. Most also face other charges such as assault on law enforcement and disrupting Congress.

Conspiracy theories

The indictment did not link Rhodes or others to Trump or members of his circle now under investigation by a Congressional committee over their role in the January 6 attack.

Rhodes has openly led the Oath Keepers since he founded the group in 2009. He is a former Army paratrooper and graduate of Yale Law School, and was on the staff of former congressman Ron Paul, a prominent libertarian.

The group is only loosely organized around the belief that the federal government is growing too powerful and can be removed by force under certain conditions, according to a recent report on them published by the Combating Terrorism Center (CTC) of the US Army's West Point military academy.

"Conspiracy theories have always been a feature" of their ideology, the report said, and they have regularly shown up in combat gear and heavily armed at politically charged protests, in shows of force that critics label as intimidation.

The group has targeted for recruitment primarily current and former military, police and first responders. A recently leaked database had 38,000 names of people who had registered with the Oath Keepers at one point or another.

'Civil war'

The indictment detailed the group's planning from text messages and chats between members beginning from the election in November 2020 through the day of January 6.

Two days after Trump's defeat, Rhodes convened Oath Keepers leaders in an encrypted chat and told them, "We aren't getting through this without civil war."

He issued a call to action, and on December 11 told the group that if Biden became president, "it will be a bloody and desperate fight... That can't be avoided."

In the following weeks, they discussed tactics for January 6 and the likelihood of violence.

Rhodes spent $18,000 ahead of the day on firearms, ammunition and other equipment including gunsights and night-vision gear for his group, the indictment said.

The indictment focuses on the way they formed two "stacks," combat-like formations, to force their way past police and into the Capitol on January 6. 

They also designed routes for their multiple armed "QRFs" to come to their aid from the Washington suburbs if fighting broke out.

The indictments on sedition charges took the January 6 investigation to a new level. Some 725 people have been charged overall, mostly for lesser charges such as illegally entering the Capitol.