Authorities stand with a robot, left, at the northwest gate to the White House during a lockdown in Washington, Monday, May 30, 2016. Secret Service spokesman Robert Hoback says someone at about 12:15 p.m. threw a metal object over the north fence along Pennsylvania Avenue and was arrested without incident. He did not identify the person, though a witness saw a woman placed in handcuffs.
(AP Photo/Andrew Harnik)
AP Photo/Andrew Harnik
Men in what appears to be a hazardous materials suits by the Northwest gate of the White House in Washington, Monday, May 30, 2016. Secret Service spokesman Robert Hoback says someone at about 12:15 p.m. threw a metal object over the north fence along Pennsylvania Avenue and was arrested without incident. He did not identify the person, though a witness saw a woman placed in handcuffs.
(AP Photo/Susan Walsh)
AP Photo/Susan Walsh
A woman is detained in Lafayette Park near the White House along Pennsylvania Avenue, in Washington, Monday, May 30, 2016. Secret Service spokesman Robert Hoback says someone at about 12:15 p.m. threw a metal object over the north fence along Pennsylvania Avenue and was arrested without incident. He did not identify the person, though a witness saw a woman placed in handcuffs.
(AP Photo/Andrew Harnik)
WASHINGTON — The White House was briefly locked down Monday afternoon after someone threw a container over the North Lawn fence.
A person was apprehended without incident, Secret Service staff said in an emailed statement. The Associated Press has since reported that a woman was detained.
An explosive ordnance team was called in to investigate the object, which was described as a metal container with some papers inside. Tourists were moved away from the fence line on Pennsylvania Avenue back to Lafayette Park.
Reporters were not allowed to venture out of the White House press room.
It was later determined that the object posed no threat; the White House has since returned to normal operations, according to the Secret Service.
President Barack Obama was in the White House at the time of the lockdown, the Associated Press reported. He had just returned from laying a wreath at the Tomb of the Unknowns as part of the annual Memorial Day observance at Arlington National Cemetery.
