Up to 25,000 U.S. National Guard troops are being deployed to the city for the inauguration of President-elect Joe Biden on Wednesday, in a massive security ramp-up after Donald Trump's supporters broke into the Capitol building.

With seven-foot barriers being erected around the Capitol, its office buildings, and the Supreme Court, the city core is in a virtual lockdown.

Vehicle traffic in much of the city is prohibited or limited to residents and businesses only. Military vehicles are seen parking at intersections downtown to boost security. Many of the restrictions are expected to remain in place until Thursday after the inauguration.

Residents said they do not recognize Washington D.C. with so many military personnel lining the streets, in a city known as a tourist attraction.

Darren Wilson, who lives just outside Washington D.C., said the troop deployment is "understandable," given the breach in security at the Capitol building that allowed rioters to penetrate.

The Capitol attack has made the city jittery, underscored by a brief shutdown on Monday, which was the result of a small fire in a homeless encampment.

"Due to an external security threat under the bridge on I-295 at First and F Streets SE, staff and other personnel are directed to avoid coming to the Capitol Complex area until further notice," Capitol Police said to lawmakers Monday morning.

"All personnel currently on the Capitol Complex are advised to stay indoors and away from windows and doors."

D.C. Fire and Emergency Medical Services said that the fire had been extinguished. It said the fire was caused by a homeless person who used propane, adding the incident resulted in one individual sustaining a "non-life-threatening injury."

On-site photos showed people inside the Capitol were evacuated from the West Front of the building. They were rehearsing the presidential inauguration.

On Friday, a man who was carrying an unlicensed firearm and over 500 rounds of ammunition was arrested at a security checkpoint.

The man, identified as Wesley Allen Beeler from Virginia, was released Saturday on personal recognizance, saying after the release that he made "an honest mistake."