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Kim Jong-un’s hermit state claimed on Sunday to have detonated a hydrogen bomb that could be fitted to a missile, leading to condemnation around the globe. And Defcon said there had now been reports of radioactive material being detected in China, South Korea and the test site itself. It is thought the source of the radiation was the collapse of the Punggye-ri test site where North Korea detonated its bomb in tunnels below Mount Mantap.

GETTY King Jong-un's regime claims to have detonated a hydrogen bomb

The testing site collapsed due both to the power of the explosion Defcon

The worrying new report said: “It is difficult to know exactly how much radiation to expect, as the radiation is likely being released due to a collapse at the nuclear test site in North Korea. “The test was done underground, but the testing site collapsed due both to the power of the explosion as well as due to repeated tests.” According to the report, unusual radiation levels were detected in Jiln and Sandong province’s near China’s order with North Korea.

GETTY North Korea has conducted six nuclear tests

Elevated readings were also found at Pungyye-ri where the bomb was detonated, Defcon said. South Korean nuclear experts, checking for contamination, also said on Friday they had found traces of radioactive xenon gas but that it was too early to link it to Sunday's explosion. The latest findings appear to contradict previous reports from earlier this week that no abnormal radiation levels had been detected near the site, leading some to believe the nuclear claim could have been a hoax.

North Korea celebrates nuclear test Thu, September 7, 2017 North Korea held a mass celebration for the scientists involved in carrying out its largest nuclear blast to date, with fireworks and a mass rally in Pyongyang Play slideshow AFP/Getty Images 1 of 17 Korean People's Army (KPA) soldiers cheer during a mass celebration in Pyongyang

The Defcon warning system, a private organisation which monitors world events and estimates the nuclear threat against America, said the amount of radiation was currently small and did not present a danger health at this time. It stated: “It is unlikely that there will be further exposure, but this can change depending on what happens at the test site.” Earlier this week, Defcon said its warning system had been raised to level 4 amid increasing tensions over the regime’s nuclear threat and fears it could start World War 3.

GETTY North Korea is marking its founding day on Saturday

The radiation findings came as South Korea braced for a possible further missile test by its neighbour, which marks the anniversary of its founding today. Japan was preparing to evacuate its citizens from South Korea fearing an attack. Speaking last week Japanese Prime Minister Shinzo Abe said: “There is a possibility of further provocations. “We need to remain extremely vigilant and do everything we can to ensure the safety of our people." Throughout the week, South Korean officials have warned the North could launch another intercontinental ballistic missile, in defiance of UN sanctions and amid an escalating standoff with the United States. Pyongyang marks its founding anniversary each year with a huge display of pageantry and military hardware. Last year, North Korea conducted its fifth nuclear test on its September 9 anniversary.