Capitol put on lockdown after fire reported several blocks away

The Capitol complex was locked down on Monday due to an "external security threat," U.S. Capitol Police said, after a fire was reported several blocks away under a nearby bridge.

An email alert sent out to lawmakers said that there was no entry or exit from the complex as of 10:30 a.m. Those inside the buildings were instructed that to stay away from exterior windows and doors. Those outside were ordered to “seek cover.”

The D.C. Fire Department noted that a nearby fire was extinguished on the 100 block of H Street SE.

A law enforcement official told NBC News that what turned out to be a fire at a homeless encampment prompted the security alert.

The Capitol is currently operating as a military zone ahead of President-elect Joe Biden’s inauguration this week, as police ramped up security after a pro-Trump mob overwhelming police to storm the building.

There are currently 7-foot barriers have been staged around the Capitol, its office buildings, and the Supreme Court.

Thousands of National Guards troops are currently quartering in the complex.