In Photos: North Korea’s Nuclear Testing Facility
Explosives are rigged inside one of the tunnels at the Punggye-ri site. The test site consists of four main tunnels beneath mountains in the north-east, according to analysis by the monitoring group 38 North.
North Korean officials watch on as one of three explosions takes place at the test site.
Photograph: NEWS 1 KOREA/EPA
An official from North Korea’s Nuclear Weapons Institute speaks about the explosions at the test site.