North Korea announces detonation of hydrogen bomb, calls it 'perfect success'

Illustration/Uday Mohite

North Korea announced it detonated a thermonuclear device yesterday in its sixth and most powerful nuclear test to date.

The North called it a "perfect success" while its neighbours condemned the blast immediately. Though the precise strength of the blast has yet to be determined, South Korea's weather agency said the artificial earthquake it caused was five to six times stronger than tremors generated by its previous tests. It reportedly shook buildings in China and in Russia. The test was carried out at 12.29 pm local time at the Punggye-ri site, where North Korea has also conducted past nuclear tests.

Officials in Seoul put the magnitude at 5.7, while the US Geological Survey said it was a magnitude 6.3. The strongest artificial quake from previous tests was a magnitude 5.3.

The North claimed the device it tested was a thermonuclear weapon, commonly called an H-bomb. It said the underground test site did not leak radioactive materials, which would make such a determination even harder.

At the same time, the simple power of the blast was convincing. Japan's Defence Minister Itsunori Onodera said it might have been as powerful as 70 kilotons. The North claims the device was made domestically and has explosive power that can range from tens to hundreds of kilotons.