_ap.jpg)
The solemn ceremony at Arlington military cemetery
The bones will be subjected to detailed analysis to see if they belong to Lieutenant Michael Blassie, a pilot who was killed in Vietnam in 1972.
The American Defence Secretary, William Cohen, had come under pressure from the Blassie family to establish whether it was their son buried at the Tomb of the Unknowns at Arlington military cemetery outside Washington.
He complied with their request, despite the arguments from Pentagon officials that the remains - buried in 1984 - could have come from any of eight other American troops lost in the area around the time that Blassie was shot down.
The disinterment took place at night. Private contractors used a diamond-tipped cutting tool to slice open thick granite slabs around the marble cover of the Vietnam War crypt at the tomb.
Then a crane lifted the heavy cover and raised the casket out of the tomb, which is visited annually by tens of thousands of Americans and tourists from around the world.
_ap.jpg)
After the private disinterment, the casket was draped with an American flag and the remains honored in a brief public ceremony before being taken in a hearse to Walter Reed Army Medical Centre for DNA gene and other tests. This may take up to three months.
The BBC Washington correspondent says that recent scientific advances may mean that the the idead of the unknown soldier is now an outdated concept.
The Tomb of the Unknowns represents tens of thousands of US military personnel killed and missing in battle.
It was created to honour those whose bodies were so maimed by the violence of war that their identities could not be determined.