North Korea has carried out its biggest ever nuclear test, a direct challenge to Donald Trump and an act which will sharply raise tensions in north-east Asia.
South Korean media said the blast was 9.8 times the strength of Pyongyang’s test last September.
Fears that Kim Jong-un’s regime had carried out the country’s sixth nuclear test came after an earthquake was detected in the reclusive state’s north-east.
North Korea state television said Pyongyang had tested a hydrogen bomb, and the test was a ‘complete success’.
Japan later confirmed that it was a nuclear test and lodged an official protest through North Korea’s embassy in Beijing.
“After analysing information from the Japan Meteorological Agency and others on the recent earthquake, the government has determined that North Korea has carried out a nuclear test,” Taro Kono, the Japanese foreign minister, told reporters after a meeting of the National Security Council on Sunday afternoon.
According to the China’s Earthquake Administration the earthquake measured 6.3 magnitude,The move is a direct challenge to U.S. President Donald Trump, who hours earlier had talked by phone with Japanese Prime Minister Shinzo Abe about the “escalating” nuclear crisis in the region.
Another estimate said the earthquake was 5.2 magnitude.
Only a few hours before the blast, North Korea has escalated tensions with a claim that it has developed a more advanced nuclear weapon with “great destructive power” capable of fitting on an intercontinental ballistic missile.
Pictures showed Kim in black suit examining a metal casing with two bulges.The official North Korean news agency, KCNA, said the hydrogen bomb was inspected by Kim Jong-un.
It was a “thermonuclear weapon with super explosive power made by our own efforts and technology”, KCNA said, with the agency adding that “all components of the H-bomb were 100 percent domestically made”.
Some have questioned whether Pyongyang has a working H-bomb.
But earlier this month, US intelligence is understood to have concluded that the rogue state has had produced a miniaturised nuclear warhead that could fit inside an ICBM.
In January last year, Pyongyang boasted that it had carried out a successful underground test of a miniaturised hydrogen bomb.
However western analysts dismissed the claims saying the six-kiloton yield was too low for a thermonuclear device.
If North Korea’s claims are true, the ability to mount a warhead on a missile would be seen as a significant escalation, creating a risk that it was preparing for an attack.
The announcement came after a series of tests by the North Korean regime, including one which saw a missile fly over Japan.