Air samples confirm N. Korea nuclear test

WASHINGTON – Air samples gathered last week contain radioactive materials that confirm that North Korea conducted an underground nuclear explosion, National Intelligence Director John Negroponte's office said today.

In a short statement posted on its Web site, Negroponte's office also confirmed that the size of the explosion was less than 1 kiloton, a comparatively small nuclear explosion. Each kiloton is equal to the force produced by 1,000 tons of TNT.

"Analysis of air samples collected on October 11, 2006, detected radioactive debris which confirms that North Korea conducted an underground nuclear explosion in the vicinity of P'unggye on October 9, 2006," the statement said.

On Friday, a senior Bush administration official told The Associated Press that one test conducted on samples gathered after the detonation found a radioactive gas consistent with a nuclear explosion. At the time, however, U.S. intelligence was not ready to confirm that a nuclear test actually had taken place.

The statement from Negroponte's office provides the first official confirmation from the United States that a nuclear detonation took place, as Pyongyang has claimed.