The US Capitol building and White House were evacuated today after a small plane entered the restricted airspace over Washington.
War planes were seen flying overhead and security cars rushed away from the buildings. President George Bush was not at the White House at the time.
A senior law enforcement official said the alarm was caused by an aircraft intruding into the protected airspace over Washington. Workers were allowed to return to the buildings within minutes of the false alarm being realised.
Sarah Little, an aide to Sen Pat Roberts, said the order to evacuate came over the special pager devices that every congressional office has.
“They said to head South because there is an imminent aircraft threat,” Little said.
Reporters in the White House were told to move to a more secure location.
A guard in the West Wing of the White House shouted at reporters: “Go down into the basement. Leave, run,” security officers shouted to staff and reporters at the Capitol building.
“This is not a drill,” guards shouted as they moved people away from the building.
Shortly after noon (5pm Irish time), officers rushed through the Supreme Court building and told staff to get into the basement. At the Treasury Department, people were moved across the street.
Several other government buildings, including the Treasury Department and the US Supreme Court ordered people to safer locations.
The security breach prompted alerts across the city.
The plane was approached by a fighter aircraft and veered away.