A dozen members of the US National Guard have been removed from duty at the inauguration of president-elect Joe Biden after vetting, which included screening for ties to right-wing extremism, Pentagon officials said on Tuesday.
There was no threat to Mr Biden, they said.
All 12 were found to have ties to right-wing militia groups or posted extremist views online, two officials told AP
The senior intelligence official and another from the Army did not say to which fringe group the Guard members belonged or in what unit they served in.
But Gen Daniel Hokanson, chief of the National Guard, confirmed on Tuesday that the Guard members had been removed and sent home.
But Gen Hokanson said only two were for removed for inappropriate comments or texts related to the inauguration.
The other 10 were for issues that might involve previous criminal activity, but not directly related to the inaugural event.
The officials said the 12 had all been removed because of “security liabilities".
It is unclear whether they will face discipline when they return home.
The National Guard Bureau referred questions to the US Secret Service.
"Due to operational security, we do not discuss the process nor the outcome of the vetting of military members supporting the inauguration," the bureau said.
The Secret Service would not comment.
On Sunday, acting Defence Secretary Chris Miller said the FBI was assisting the US military in vetting more than 25,000 National Guard troops being sent to protect the US capital.
"As is normal for military support to large security events, the department will vet National Guardsmen who are in Washington," Mr Miller said on Monday.
"While we have no intelligence indicating an insider threat, we are leaving no stone unturned in securing the capital.
"This type of vetting often takes place through law enforcement for significant security events. However, in this case the scope of military participation is unique."
The vetting began last week to help address concerns over possible insider attacks.
The FBI is also working to see if any attackers from the January 6 riot at the US Capitol are current service members.
Last week, the Virginia National Guard said that Jacob Fracker, an off-duty police officer charged in connection with the violent riot at the Capitol, was a corporal in the state's Guard and served as an infantryman.
There will be about 25,000 members of the National Guard stationed in Washington when Mr Biden is sworn in on Wednesday.
The FBI has said there is a potential for follow-up attacks after the Capitol riot.