Tunnel collapse may have killed 200 after North Korea nuclear test: Japanese broadcaster

National Earthquake and Volcano Centre director Lee Mi Seon displaying a map of North Korea while speaking about an "artificial earthquake", believed to be caused by a nuclear test, on Sept 3, 2017. PHOTO: AFP

TOKYO (REUTERS, AFP) - A tunnel at North Korea's nuclear test site collapsed after Pyongyang's sixth atomic test in September, possibly killing more than 200 people, Japanese broadcaster TV Asahi said on Tuesday (Oct 31), citing unnamed sources familiar with the situation.

Reuters has not been able to verify the report.

About 100 workers at the Punggye-ri nuclear site were affected by the initial collapse, which took place around Sept 10, the broadcaster said. A second collapse during a rescue operation meant it was possible the death toll could have exceeded 200, it added.

Experts have warned that the underground tests could cause the mountain to collapse and leak radiation into the atmosphere near China's border. The latest test - the sixth at the site since 2006 - triggered landslides in the detonation area and beyond, according to satellite pictures taken the day after.

The images published by the 38 North website showed changes in the surface at Punggye-ri where the ground had been lifted into the air by the tremors. Small landslides followed the course of stream beds.

The blast caused a 6.3-magnitude earthquake, according to the US Geological Survey, followed a few minutes later by another with a magnitude of 4.1. Japan assessed the yield from the test of what the North said was a hydrogen bomb at 120 kilotons, eight times the size of Hiroshima in 1945.

It is very unusual for North Korea to acknowledge any major accident, especially anything that involves its nuclear programme.

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Catch a glimpse of daily life in North Korea, one of the world's most reclusive countries. The Straits Times spent a week in its capital Pyongyang in October.

Eugene Lee, a spokeswoman at South Korea's unification ministry, said: "We are aware of the report but do not know anything about it."

The report came ahead of US President Donald Trump's first presidential visit to South Korea next week amid an escalating war of words between him and North Korean leader Kim Jong Un.

The reclusive country has made significant strides in its atomic and missile technology under Kim, who took power after the death of his father and longtime ruler Kim Jong Il in 2011. Since then he has overseen four of the country's six nuclear tests and hailed atomic weapons as a "treasured sword" to protect the nation from invasion by the United States.

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