Over 200 people were reportedly killed when tunnels at North Korea’s nuclear test site collapsed after a hydrogen bomb test, Japan’s Asahi TV reports.
The incident is said to have occurred while a tunnel was in the process of construction at Punggye-ri.
One hundred workers died in the initial accident and over two hundred more died during a rescue operation, as there was another collapse.
The test site was affected by the sixth nuclear blast on September 3rd which involved a 100-kiloton hydrogen bomb and was about seven times more powerful than the Hiroshima atomic bomb dropped by the US in 1945.
It is believed that the ground may have become loose due to the sixth nuclear test conducted in September.
Experts say there have been a series of tremors and landslides near the nuclear test site, which meant that the sixth and largest blast has destabilized the site, and it might not be used for much longer to test nuclear weapons.
South Korea’s Intelligence Service said that North Korea was preparing two new tunnels for future tests after the test of the hydrogen bomb.