As North Korea claims it has successfully tested a hydrogen bomb, here is a list of its previous claimed nuclear tests.
Oct. 9, 2006
North Korea’s says they had their first underground nuclear test at Punggye-ri, also known as Punggye-yok, a remote area in the Northeast near the town of Kilju.
They say the blast was based on plutonium and its explosive force, relatively small, was less than 1 kiloton.
Pyongyang gave an advance warning to the international community, six days prior, of its intention to test the nuclear device.
Days later, the U.N. Security Council unanimously approved military and economic sanctions against North Korea.
May 25, 2009
Barely a month after North Korea walked out of international talks on its nuclear program, it claimed to conduct a second underground test, saying that they detonated a plutonium nuclear device.
This time, the power of the explosion was equivalent to U.S. bombs that destroyed Hiroshima and Nagasaki, Japan, in 1945.
Although North Korea did not specify the location, a 4.7-magnitude quake was detected near the first nuclear test site, Punggye-yok.
The claimed underground bomb test followed hard on the heels of the test of a long-range missile in April 2009.
North Korea claimed it succeeded, but the missile flew only 90 seconds after takeoff.
Feb. 12, 2013
North Korea claimed to launch its third underground nuclear test after unusual seismic activity was detected near the same Punggye-ri nuclear site.
The United States Geological Survey confirmed a magnitude-5.1 artificial earthquake.
This time North Korea claimed to have developed a lighter miniaturized nuclear device to fit on the top of the long-range missiles that could reach the mainland of United States.
South Korea’s Defense Ministry estimated the yield to be approximately 6 to 7 kilotons.