North Korea is believed to have launched a ballistic missile from a submarine in the Sea of Japan, the South Korean military has said.

However South Korea’s Joint Chiefs of Staff told news agency Yonhap that the missile flew for just 30km compared to the usual 300km-minimum range of a submarine-launched ballistic missile (SLBM).

The potential missile launch comes almost a year after Pyongyang announced it had carried out a successful underwater SLBM test in May, with two further unsuccessful tests carried out towards the end of the year prior to the submarine being damaged.

Philip Hammond said the "provocation" showed North Korea’s disregard for its international obligations.

“This latest provocation, yet another violation of UN Security Council Resolutions, underlines the threat that North Korea presents to regional and international security," the Foreign Secretary added.

“In conducting this test, North Korea has again shown its blatant disregard for its international obligations and the UK will be working on a strong multilateral response through the UN and EU.”



In pictures: North Korea hydrogen bomb test Show all 15 1 /15 In pictures: North Korea hydrogen bomb test In pictures: North Korea hydrogen bomb test In pictures: North Korea hydrogen bomb test In pictures: North Korea hydrogen bomb test A lab employee from the Korea Institute of Nuclear Safety's regional office in Gangneung, east of Seoul, checks for radioactive traces in the air, in Gangneung, soon after North Korea announced it successfully conducted a hydrogen bomb test. The office in Gangneung is the closest one to the site of the North's claimed test. Officials said it will take three to four days to analyze air samples in detail for any traces of radioactivity, the Yonhap news agency reported EPA In pictures: North Korea hydrogen bomb test In pictures: North Korea hydrogen bomb test In pictures: North Korea hydrogen bomb test North Korean leader Kim Jong-Un signing a document of a hydrogen bomb test in Pyongyang In pictures: North Korea hydrogen bomb test People watch a TV news program showing North Korea's special announcement at the Seoul Railway Station in Seoul, South Korea AP In pictures: North Korea hydrogen bomb test Kuo Kai-wen, director of Taiwan's Seismology Center, explains the locations from a monitor showing North Korea's first hydrogen bomb test site, in Taipei Getty Images In pictures: North Korea hydrogen bomb test Kuo Kai-wen, director of Taiwan's Seismology Center, points at the curves chart received from Taiwan showing North Korea's first hydrogen bomb test, in Taipei Getty Images In pictures: North Korea hydrogen bomb test In pictures: North Korea hydrogen bomb test In pictures: North Korea hydrogen bomb test South Korean people watch TV news at Seoul station EPA In pictures: North Korea hydrogen bomb test Japan's meteorological agency officer Yohei Hasegawa displays a chart showing seismic activity, after a North Korean nuclear test, at the agency in Tokyo Getty Images In pictures: North Korea hydrogen bomb test Ko Yun-Hwa, administrator of Korea Meteorological Administration, briefs reporters showing seismic waves from the site of North Korea's hydrogen bomb test, at his office in Seoul Getty Images In pictures: North Korea hydrogen bomb test North Korea's border county of Kaepoong is seen from a South Korean observation post in Paju near the Demilitarized zone dividing the two Koreas as North Korea announced it had successfully carried out its first hydrogen bomb test Getty Images

The reclusive country was hit by international sanctions following a fourth nuclear test in January this year, while Seoul is closely watching Pyongyang as a fifth nuclear test is expected to take place soon.

The fifth test is rumoured to involve a small nuclear warhead that can be fitted to a ballistic missile, prompting the South Korean military to go on high alert and igniting fears the missile launch is linked to the nuclear test.

Satellite images have shown activity at the Punggye-ri test site, including what it thought to be the excavation of tunnels at the site.