Twelve members of the US National Guard have been removed from duty, as part of security measures ahead of President-elect Joe Biden's inauguration.
Two of those removed had made "inappropriate comments or texts", according to National Guard Chief Army General Daniel R. Hokanson.
The FBI has been vetting all 25,000 National Guard troops coming into Washington DC for the ceremony.
At least two-and-a-half times the usual number of National Guardsmen and women have been deployed, compared to previous inaugurals.
"If there are reported issues, our leaders will address them immediately, in accordance with established department policies, and include ordered coordination with law enforcement," Gen Hokanson said.
"I'm not concerned [about] a large part of our organisation," he added.
"If you look at 25,000, we've had 12 identified... But we want to make sure, out of an abundance of caution, that we do the right thing until that gets cleared up."
Pentagon spokesperson Jonathan Hoffman declined to specify the details of what exactly had led to the 12 National Guard members being removed but stated: "Much of the information is... unrelated to the events taking place at the Capitol.
"These are vetting efforts that identify any questionable behaviour in the past or any potential link to questionable behaviour, not just related to extremism.
"Right now, we're not asking questions of people who are flagged.
"We're, out of an abundance of caution, taking action and immediately removing them from the line of duty at the Capitol and the events taking place," the Pentagon spokesman added.
"Then we will address them, whether it's through law enforcement, if necessary, or through their chain of command."
During the inauguration ceremony, Mr Biden will oversee a Pass In Review – a military tradition honouring the peaceful transfer of power to a new commander-in-chief.
The President-elect and Vice President-elect Kamala Harris will then lay a wreath at the Tomb Of The Unknown Soldier, joined by a trio of bipartisan former US presidents, Barack Obama, George W. Bush and Bill Clinton.
Cover image: PA.