A small drone that crashed on the South Lawn of the White House was operated by a government employee who said it breached the secure perimeter by accident, US media are reporting.
The New York Times said the employee does not work for the White House and told the US Secret Service he was flying the unmanned quad copter aircraft recreationally before he lost control.
The device, approximately two feet (61 cm) in diameter, was spotted flying at a low altitude at about 3am local time before it crashed on the southeast side of White House grounds, the Secret Service ssaid in a statement.
White House spokesman Josh Earnest told reporters traveling with President Barack Obama in India on Monday that the Secret Service - the agency that protects Obama and his family, and secures the White House grounds - was investigating.
US regulators are working to draft new rules for commercial drones used for farming and news gathering. The small remote-controlled aircraft also have become popular as toys, raising privacy concerns as well as safety issues after close calls with jets.
The Secret Service also has come under scrutiny after several incidents. Its director resigned in October, and an independent review concluded that it needs to build a better fence and hire more officers.
Mainor said there was an "immediate alert and lockdown of the complex until the device was examined and cleared."