South Korea spy agency believes bomb was atomic

A South Korean lawmaker says the country’s spy agency told him in a private briefing that Pyongyang may not have conducted a hydrogen bomb test given the relatively small size of the seismic wave reported.

Lawmaker Lee Cheol Woo says the National Intelligence Service told him that an estimated explosive yield of six kilotons and a quake with a magnitude of 4.8 were detected Wednesday.

According to him, that’s smaller than the estimated explosive yield of 7.9 kilotons and a quake with a magnitude of 4.9 that were reported after the 2013 nuclear test, and only a fraction of a typical successful hydrogen bomb test’s explosive yield of hundreds of kilotons.

Lee says the agency told him that even a failed hydrogen bomb detonation typically yields tens of kilotons. Lee sits on the parliament’s intelligence committee.