North Korea on Sunday conducted its sixth nuclear test. The detonation was first detected as a manmade earthquake, which was 10 times more powerful than the tremors created by its test last year.
In a statement Pyongyang said the detonation was of an advanced hydrogen bomb, rather than an atomic device, and said it was a "perfect success".
The test comes amid heightened tensions between North Korea and the US over recent weeks as Pyongyang remains defiant in the face of US calls to dismantle its development of nuclear weapons.