Important source added on January 9, 2015.
KCNA - Korean Central News Agency (Pyongyang, North Korea)
Today early in the morning, North Korea carried out a nuclear test that should have been the first test of a hydrogen bomb. However, Western sources still doubt it was a successful test as the announced kind of weapon should have produced a much higher effect than was detected by sophisticated seismic observation in the U.S.A..
On the same day, China's news agency XinHua compared seismic data collected in China and the U.S.A.:
On [January] 6 and according to a separate report from the Korean Central News Agency (朝鲜中央通讯社), North Korea's supreme leader Kim Jong Un, on December 15 and on behalf of the North Korean Workers' Party, made known to have given the order for the test of a hydrogen bomb, and he signed the final order on January 3 .
On [January] 6 at about 10:00 am, a correspondent of XinHua agency, while gathering news in Pyongyang, did not feel a [seismic shock]. In the capital Pyongyang all streets [remained untouched].
The center for China's network of seismic stations issued information that on [January] 6 at 01:30 GMT (i.e. 09:30 Beijing local time) North Korea experienced a 4.9 degree [seismic shock], its center located at 41.3 degrees north latitude and 129.1 degrees east longitude, the [seismic] focus lying at a depth of 0.0 km.
Separately, the U.S. Geological Survey Earthquake Information Network reported a [seismic shock] of 5.1 degrees on [January] 6 at 01:30 GMT (09:30 Beijing Time), the seismic center being located at 41.3085 degrees north latitude and 129.0337 degrees east longitude, the focus at a depth of 10.0 km.
North Korea earlier declared having separately carried out three subterranean nuclear tests in 2006, 2009 and 2013.
[Source: People's Network on January 6, 2016]
The North Korean H-bomb explosion is probably a fake.
[Strength of explosion] is not reaching an atomic bomb.
[Source: Military site of Ifeng news center on January 6, 2016]
North Korea declares to possess a H-bomb
and ulterior motives are exposed to the sun.
China rapidly makes clear its position.
Why did Kim Jong Un decide to raise
the item of a H-bomb just at this time ?
Last December (2015), a semi-official Chinese news source already discussed the capability of Kim Jong Un's North Korea to build a H-bomb:
据朝中社10日报道，近日，朝鲜领导人金正恩突然宣布朝鲜目前已经掌握了氢弹技术。 此番言论并未如以前金氏在朝核问题上的表态那般在国际社会引起轩然大波，只有中国 外交部第一时间作出反应，表示坚持半岛无核化立场。
According to a report from the [North] Korean Central News Agency on [December] 10 , North Korea's leader Kim Jong Un unexpectedly declared that North Korea at present already controls the H-bomb technology. This remark is not [the same] like a previously stated standpoint of Kim in the frame of the North Korean nuclear subject and which caused a mighty uproar of the international community. [However] only China's ministry of foreign affairs showed a first time reaction and made clear [it would] insist on [its] position of inhibiting nuclear proliferation on the Korean peninsula. .....
Is North Korea really capable of building a H-bomb ?
=> Result of the Chinese article's evaluation:
From the earlier mentioned [facts] follows that difficulties [will be] unusually high to use a small-sized atomic bomb as the detonator of a H-bomb.
[Source: China.com / CRI online (China Radio International) 国际在线 on December 14, 2015]
The war of nerves continues .....