A man has been arrested after illegally landing a gyrocopter on the west lawn of the US Capitol in Washington DC.Nearby streets were closed and the Capitol Visitor Center placed on lockdown as a bomb squad investigated.
Authorities did not immediately name the pilot, but a Florida postman named Doug Hughes took responsibility for the stunt.
He said he was delivering letters to all 535 members of Congress in order to draw attention to campaign finance corruption.
John Jewell, 72, a tourist, told AP news agency the craft bounced as it landed and an officer was waiting with gun drawn.
A robot bomb detector was sent to the aircraft, which apparently bore the logo of the US Postal Service, but nothing hazardous was found.
US President Barack Obama has been briefed about the incident.
According to the Tampa Bay Times, Mr Hughes brought letters to lawmakers declaring a “voter’s rebellion”.
The material reportedly said: “As a member of Congress, you have three options. 1. You may pretend corruption does not exist. 2. You may pretend to oppose corruption while you sabotage reform. 3. You may actively participate in real reform.”
House Homeland Security panel chairman Michael McCaul said authorities had been prepared to shoot down the pilot if he flew any closer to the Capitol.
Mr Hughes told the Tampa Bay Times the US Secret Service had questioned him about his plans last year.
He has criticised the Citizens United ruling, which allowed corporate donations to US political campaigns to be qualified as free speech.
Capitol Police Lt Kimberly Schneider said charges are pending against the man in custody.
Air space is restricted around Washington landmarks, including the White House and the Capitol.
The incident was in apparent violation of the no-fly zone.
The breech was the latest security scare in Washington.
On Saturday, a man holding a protest sign shot and killed himself near the steps of the US Capitol.