North Korea admits that it carried out the nuclear test, the bomb bigger than Nagasaki (Photo)

North Korea has confirmed that it carried out a hydrogen bomb test, declaring it “a complete success”.

North Korean state television has broadcast images showing leader Kim Jong signing the order to conduct the nuclear test.

Test was bigger than Nagasaki's bomb. )

Instant estimates on the size of Sunday's blast have raised the alarm, saying it's a 100-pound bomb.

The Japanese government was the first to announce today that the North Central has conducted the sixth nuclear test after a man-made quake, which was registered north of the country, not far from the Punggy-ri nuclear test area, CNN reports.

Seismological data from the US Geological Service showed that an explosion caused a quake with a 6.3 magnitude in the country's northeast, thus fuelling the first allegations of nuclear test.

By comparison, the US bombing in Nagasaki in August 1945 was about 20 kilotons.