The US Capitol is locked after Capitol Hill officers were injured outside the building

“(United States Capitol Police) respond to the North Barricade Vehicle Access Point along (Constitution) Avenue for reporting that a person had run into a vehicle in two USCP officers. A suspect is in custody. The two policemen are injured. All three were rushed to hospital, ”USCP said in a tweet Friday.

An initial USCP alert warned of an “outside security threat” to the Capitol and an announcement over the complex’s public address system told everyone to stay inside and away from windows.

CNN’s Lauren Fox reports seeing ambulances and a helicopter outside the building. One person was seen on a stretcher.

DC Fire spokesman Vito Maggiolo said the department was responding to a reported shooting against the North Capitol barricade and there were indications it would be transporting patients.