WASHINGTON - US intelligence has detected an explosion of less than one kilotonne in magnitude in North Korea but has not been able to determine whether it was nuclear or not, a senior intelligence official said Monday.
The official, who asked not to be identified, said that first-time nuclear tests historically have been in the several kilotonne range.
"We are aware that there was a sub-kilotonne explosion in North Korea," said the official. "We have not been able to determine at this point whether it was in fact nuclear."
North Korea announced earlier that it had conducted an underground nuclear test, calling it an "historic event" that would contribute to peace and stability on the Korean peninsula.
Other experts around the world reported a seismic event on the Korean peninsula that registered between 3.58 and 4.2 on the Richter scale. Norwegian monitors said their readings indicated an explosion of between one and 10 kilotonnes.
10/09/2006 15:27 GMT