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White House analysis casts doubt on North Korea's nuclear test claims

North Korea says it has successfully conducted a test of a miniaturised hydrogen nuclear device on Wednesday morning.

However, the White House has said initial analysis of the reported nuclear test is not consistent with claims of a successful hydrogen bomb.

In a statement the country said it would continue to strengthen its nuclear programme as long as the US maintained what it called "its stance of aggression."

Much of the international community has condemned North Korea after the claim, including China, the country's major ally, and Britain, which said the move was a "provocation".

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Tremor caused by blast 'too small for H-bomb'

A South Korean map showing the seismic waves observed after the apparent nuclear test. Credit: Reuters

South Korea's military have played down the apparent successful test of a North Korean nuclear weapon, saying that that tremor it caused wasn't strong enough for a H-bomb.

A source, who asked to remain anonymous, told the Yonhap state news agency in South Korea that 5.1 magnitude earthquake apparently caused by the bomb was too slight to be a hydrogen device:

"It is hard to regard this test as that of a hydrogen bomb.

Only a few countries including the US and Russia have conducted hydrogen bomb tests and size of detonations reached 20 to 50 megatons."

The latest North Korean test amounted to around six kilotons and is "too weak" for a h-bomb, the official claimed.

But announcing the test, Pyongyang said it had successfully detonated a "miniaturised" device, which could explain its relatively small size in comparison to conventional nuclear weapons.

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