The Secret Service said the White House is back to normal operations after someone threw an object over the fence along Pennsylvania Avenue.
The person threw the item about 1:15 p.m. over the fence on the north side of the White House, near Lafayette Square, according to D.C. Fire and EMS. The Secret Service said the object was metal, but inspection of the object showed it was not harmful.
A woman was detained and placed in handcuffs.
The lockdown ensued shortly after President Barack Obama returned from delivering a Memorial Day speech at Arlington National Cemetery.