A DEADLY radioactive could could engulf the "entire hemisphere" killing thousands if North Korea’s nuclear facility collapses following its recent test launch.
Chinese geologists today warned their North Korea counterparts that the Punggye-ri underground nuclear facility may collapse if future tests are carried out at the same location.
Experts claimed future testing might "blow the top off the mountain," spreading radioactive waste through the wind and cracks created during the implosion.
And they suggested the deadly radiation cloud could spread across the entire hemisphere sparking a major global disaster.
The dangerously high levels of radiation could kill thousands or even millions - perhaps not instantly, but over the following weeks, months and years.
A researcher at the country's Peking University, said: “China cannot sit and wait until the site implodes.
“Our instruments can detect nuclear fallout when it arrives, but it will be too late by then.
“There will be public panic and anger at the government for not taking action.”
READ MORE: Hundreds dead at North Korea's nuclear missile testing facility after tunnel collapse
Lan Xiaoqing, a researcher at the Institute of Atmospheric Physics Associate, said: “The fallout can spread to an entire hemisphere.”
All of North Korea's nuclear tests have been conducted at the Punggye-ri test site - which is built into Mount Mantap.
While the exact locations of the nuclear tests themselves remain a mystery, seismologists believe they can pinpoint it to a 100-metre area.
While a test site could be operated safely at such a location, unsophisticated engineers are believed to have increased the risk of disaster with crude drilling techniques.
Punggye-ri was also the site of North Korea’s sixth-ever nuclear test on September 3, which caused a huge earthquake and sparked a series of smaller tremors and landslides ever since.
Foreign experts and human rights activists had warned this month of the danger of despot Kim Jong-un’s crumbling facilities.
On Monday South Korea warned another nuclear test at the site could lead to a total collapse of the mountain facility, causing a deadly leak of radioactive materials.
And today it was revealed today that around 100 people were killed when an unfinished tunnel collapsed at North Korea’s Punggye-ri facility.
Another group of around 100 people subsequently died while attempting to rescue the entombed workers.
The disaster was revealed by Japan’s TV Asahi today, although they could not clarify when the accident and subsequent doomed rescue attempts took place.
They said North Korean sources told them the collapse occurred as workers were working on the new tunnel. A second collapse took place as workers tried to rescue their colleagues.
The collapse is seen as evidence the September 3 test destabilised the mountainside facility after North Korea tested a huge 100-kiloton explosive which was around seven times as powerful as the bomb dropped on Hiroshima during WW2.
Paul Richards, a seismologist at Columbia University's Lamont-Doherty Earth Observatory, said: “What we are seeing from North Korea looks like some kind of stress in the ground.
"In that part of the world, there were stresses in the ground, but the explosions have shaken them up."
North Korea has not engaged in any missile or nuclear provocations since mid-September.
But chilling satellite photos suggest North Korea could be ready to launch another nuclear test with no warning the moment crackpot leader Kim Jong-un decides to push to the button.
Grainy images of the Nampo Naval shipyard on the hermit kingdom’s west coast show Kim is continuing to work on his second barge so his navy can carry out underwater test missile launches.
The 68ft barge is identical to another seen at the Sinpo South shipyard on the east coast which has been involved in up to six test launches since 2014.
According to 38 North, which monitors North Korea, it could suggest the hermit state is expanding the submarine-launched ballistic missile and development programme to the west coast.
Experts believe the aerial images of the Punggye-ri Nuclear Test Facility also show a central ring that is used to support a missile launch tube during testing.