Tremors caused by a suspected nuclear test in North Korea were at least ten times as powerful as the last time Pyongyang exploded an atomic bomb a year ago, the Japan Meteorological Agency (JMA) said on Sunday.
“It was a least ten times as powerful,” a JMA official said at a briefing aired by public broadcaster NHK.
The previous nuclear blast in North Korea is estimated by experts to have been around 10 kilotons.