The entire U.S. Capitol complex was on lockdown Monday morning after a fire was reported several blocks away, Capitol Police said in a letter to lawmakers.

“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,” read the alert.

“All personnel currently on the Capitol Complex are advised to stay indoors and away from windows and doors,” the police added.

D.C. Fire and Emergency Medical Services said on Twitter that it “responded to an outside fire in the 100 block of H St SE that has been extinguished.

There were no injuries. This accounts for smoke that many have seen.” (Xinhua/NAN)