The United States developed lightweight nuclear weapon thirty years ago

The United States government has released previously secret information on the development more than thirty years ago of a lightweight nuclear weapon which could be deployed by a single soldier.

One film, among the documents now de-classified, shows a navy diver practising with such a device: it's yield is described as about fifteen times smaller than the nuclear bomb dropped on Hiroshima in 1945, but still capable of causing enormous damage.

Washington says the weapon was never used.

The declassified documents also include data on twenty-seven atomic explosions under the Nevada desert in the 1960's and '70's designed to find peaceful uses for nuclear energy.

From the newsroom of the BBC World Service