WASHINGTON - The roughly 25,000 National Guardsmen deployed to the U.S. capital to ensure President-elect Joe Biden is able to be sworn in peacefully went through an additional background check to weed out any whiff of domestic extremism.

Added for one of the most fraught deployments in the history of the Guard, the screening is “about the same” as the standard background check that Guardsmen go through when they initially enlist, the commanding general of the D.C. National Guard said in an interview on Saturday. It is intended as “another layer” of security on top of continuous monitoring of the force, he said.

“For this deployment everybody is screened additionally, but it’s more of a reassurance, because we do everything we can do know our Guardsmen, our soldiers and airmen,” Major General William Walker said.

A spokesman for D.C. Guard declined to say how many Guardsmen were rejected for the deployment during the screening process, citing operational security.

The Defense Department broadly has struggled to get a handle on the problem of extremism, including white supremacy, in its ranks. A senior official told reporters that the Pentagon has seen an increase in white supremacist beliefs among both active duty service members and veterans, but was unable to provide concrete figures. Several people arrested in connection with the Jan. 6 assault on the U.S. Capitol were current and former military members and at least one person arrested is a member of the Virginia National Guard.