North Korea 'successfully fired ballistic missile from submarine' just weeks before claimed hydrogen bomb test

Revelation appears to show Pyongyang is working on both creating a nuclear bomb and developing ways to launch it

Pyongyang reportedly conducted an ejection test of the submarine-launched ballistic missile in December (Reuters)

As the world reacts to claims North Korea has successfully launched a hydrogen bomb, it has emerged Pyongyang’s previous test included the launch of a ballistic missile from a submarine.

The chilling revelations appear to show the hermit state is simultaneously working to build both a viable nuclear bomb and a practical method by which an atomic warhead could be launched.

South Korea's Yonhap News Agency cited an unnamed South Korean government official as saying Pyongyang appeared to have conducted an ejection test of the submarine-launched ballistic missile (SLBM) in December, following a reported failure of such a test in November.

A South Korean military official told Reuters that North Korea continued to developed submarine-launched missile capability but expects it will take a substantial period of time for it to be able to successfully deploy such a weapon.

News of the submarine launch comes as North Korea claimed to have conducted a powerful hydrogen bomb test, a defiant and surprising move that, if confirmed, would be a huge jump in Pyongyang's quest to improve its nuclear arsenal.

Screens in Seoul show the earthquake near North Korea's nuclear facility (AP)

In a passionate broadcast, a state television anchor said the North had tested a "miniaturised" hydrogen bomb, in a "perfect success", elevating the country's "nuclear might to the next level" and providing it with a weapon to defend against the US and its other enemies. South Korea's defence ministry said that it was bolstering its security posture in response.

There has long been scepticism by Washington and nuclear experts on past North Korean claims about H-bombs, which are much more powerful and much more difficult to make than atomic bombs. But a confirmed test would be seen as extremely worrying and lead to a strong push for new, tougher sanctions on North Korea at the United Nations.

The UN Security Council has tentatively scheduled an emergency meeting for later today.

Additional reporting by PA