North Korea says it has successfully carried out its fifth nuclear test.
The announcement on state media came hours after a seismic event was detected near its nuclear test site.
South Korea believes it is the North’s biggest-ever test, raising fears it has made significant nuclear advances.
South Korean President Park Geun-Hye called it an act of “self-destruction” showing the “maniacal recklessness” of Leader Kim Jong-Un. The US warned of “serious consequences”.
China’s Foreign Ministry said China was resolutely opposed to the test and urged North Korea to avoid further action that would worsen the situation.
Japan’s Prime Minister Shinzo Abe said his country “absolutely cannot condone” any such test and would “protest adamantly” to Pyongyang.