North Korea says it has successfully tested a nuclear weapon that could be loaded onto a long-range missile.
The secretive communist state said its sixth nuclear test was a “perfect success”, hours after seismologists had detected an earth tremor.
Pyongyang said it had tested a hydrogen bomb – a device many times more powerful than an atomic bomb.
Analysts say the claims should be treated with caution, but its nuclear capability is clearly advancing.
North Korea last carried out a nuclear test in September 2016. It has defied UN sanctions and international pressure to develop nuclear weapons and to test missiles which could potentially reach the mainland US.
South Korean officials said the latest test took place in Kilju County, where the North’s Punggye-ri nuclear test site is situated.
The “artificial quake” was 9.8 times more powerful than the tremor from the North’s fifth test, the state weather agency said.
It came hours after Pyongyang said it had miniaturised a hydrogen bomb for use on a long-range missile, and North Korean leader Kim Jong-un was pictured with what state media said was a new type of hydrogen bomb. State media said the device could be loaded on to a ballistic missile.
Initial reports from the US Geological Survey put the tremor at 5.6 magnitude with a depth of 10km (six miles) but this was later upgraded to 6.3 magnitude at 0km. This would make it the North’s most powerful nuclear test to date.
Japan condemned the test and South Korean President Moon Jae-in convened emergency security council talks. (Courtesy BBC)