More than 15,000 National Guard members have descended upon Washington, D.C. in recent days amid increasing concerns about safety at the 2021 presidential inauguration, NBC Washington reported. The unprecedented security measures follow the Jan. 6 domestic terrorism attack on the U.S. Capitol.

Several suspicious plots have been foiled in recent days. One suspect was arrested at a security checkpoint in Washington on Friday after he flashed an unauthorized inauguration credential, The New York Times reported. Police said they also found several gun-related bumper stickers, a loaded Glock pistol, 509 rounds for the pistol and 21 shotgun shells in his truck.

The 31-year-old contractor, identified as Wesley A. Beeler, spoke to The Washington Post, describing the incident as "an honest mistake."

“I pulled up to a checkpoint after getting lost in D.C. because I’m a country boy,” he told The Post. “I showed them the inauguration badge that was given to me.”

A federal law enforcement official said Beeler's credential was issued by the Park Police but was not recognized by the police officer. 

A 63-year-old woman named Linda Magovern was also arrested at an inauguration checkpoint Saturday, accused of impersonating a law enforcement officer and fleeing from police, NBC Washington reported. Police said Magovern described herself as an officer and “a part of the presidential cabinet.” She also presented a military police challenge coin, which is used by law enforcement and members of the military to recognize achievement. 

On Sunday, a Virginia man was arrested for carrying an unlicensed pistol and a large amount of ammunition near the Capitol, according to ABC 7.  

According to The New York Times, law enforcement officials said there is an alarming amount of chatter among far-right groups and other racist extremists who are threatening to disrupt the inauguration to protest President-elect Joe Biden’s electoral victory against President Donald Trump. The soon-to-be-former president has played a role in the increasing violence, fueling his base with allegations of election fraud, as Blavity previously reported.

Federal officials said they are taking several steps to stop the potential return of the Trump supporters who breached the Capitol earlier this month, including restricting their ability to board commercial planes. The security measures also include the closure of four bridges between D.C. and Virginia on Inauguration Day.

The National Park Service and U.S. Park Police added that Memorial Bridge was already shut down on Friday and will stay closed until at least Thursday. More than 25,000 National Guard members are still scheduled to arrive in the district over the next few days, aiming to protect the region which is facing threats from armed insurgents and possible attempts to plant explosive devices at so-called soft targets.

Despite the safety concerns, Biden has insisted on holding the inauguration ceremony outdoors, according to The Atlanta Journal-Constitution.