Tunnel collapse at North Korea's nuclear test site, 200 feared dead

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 said a series of tremors and landslides near the nuclear test base probably mean the country’s sixth and largest blast on Sept. 3 has destabilised the region, and the Punggye-ri nuclear site may not be used for much longer to test nuclear weapons.