North Korea announces successful hydrogen bomb test - world reaction to Kim Jong-un's latest nuclear step

• Updated 11:25, 6 January 2016
• 
  

North Korea leader Kim Jong-un authorised the H-bomb test - a move condemned around the world. The explosion, the secretive nation's FOURTH nuclear test, caused a massive earthquake

North Korea has come under fire from nations across the globe after claimed it had successfully tested a hydrogen bomb.

Seismic activity from the region appears to support the secretive state's claim that it had detonated a H-bomb underground.

Britain, the United States, Russia, Japan and the United Nations have all strongly condemned the nation, while South Korea has posted troops to the border.

Key Events So Far

• 10 mins ago What is a hydrogen bomb and what can it do?
• 1 hour ago "Thrilling sound of our first hydrogen bomb"
• 2 hours ago South Korea troops 'circle border'
• 2 hours ago UN Security Council to meet
• 2 hours ago US will respond "appropriately"
• “Given the scale, it is hard to believe this is a real hydrogen bomb,” said Yang Uk, a senior research fellow at the Korea Defence and Security Forum.

“They could have tested some middle stage kind (of device) between an A-bomb and H-bomb, but unless they come up with any clear evidence, it is difficult to trust their claim.”

Joe Cirincione, a nuclear expert who is president of Ploughshares Fund, a global security organisation, said North Korea may have mixed a hydrogen isotope in a normal atomic fission bomb.

“Because it is, in fact, hydrogen, they could claim it is a hydrogen bomb,” he said.

“But it is not a true fusion bomb capable of the massive multi-megaton yields these bombs produce”.

11:25 Key event

What is a hydrogen bomb and what can it do?

A hydrogen bomb, or H-bomb, is the informal term for a thermonuclear device.
They are detonated in two stages, the first a nuclear fission reaction that then ignites a secondary nuclear fusion reaction.
Fission is another word for splitting, so the energy in a nuclear fission blast is created when the nuclei of materials like uranium or plutonium are split.