(WASHINGTON) — The Cannon House Office Building, a congressional office building in Washington, D.C., was evacuated via underground routes Thursday morning due to a suspicious vehicle, according to a law enforcement sources.

The Capitol Police in a tweet called it “an active bomb threat investigation.”

Messages have been sent to congressional staffers asking that they “remain calm and relocate to Longworth House Office Building using the underground tunnels.”

The Library of Congress is also being evacuated, sources told ABC News.

The FBI said it’s responding. The White House is monitoring the situation and is receiving updates from law enforcement, according to an administration official.

Congress is in recess.

This is a developing story. Please check back for updates.
 

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