North Korea on 3 September 2017 announced that it successfully tested a hydrogen bomb that can be placed on an intercontinental ballistic missile.
The announcement was made by the state news agency after geological agencies registered a man-made quake in the northeast of the country.
As per the analysts, previous North Korean nuclear tests have resulted in earthquakes; however, a 6.3 magnitude tremor indicates that the size of the nuclear test was larger than previous ones.
South Korea's Meteorological Administration estimated that the test was five to six times more powerful than North Korea's fifth nuclear test in September 2016, which caused a 5.3 magnitude earthquake. It said it was about 10 times stronger than a nuclear test in January 2016.
The nuclear test was condemned worldwide. In fact, South Korea and Japan called for new United Nations sanctions on North Korea.
Nuclear tests conducted by North Korea
9 October 2006: Reportedly, it was a fizzle. The Federal Institute for Geosciences and Natural Resources, a state-run geology research institute in Germany, estimated the yield by the test at 2 kilotons back in 2013; however, the yield has since been revised to 0.7 kilotons.
25 May 2009: The Federal Institute for Geosciences and Natural Resources estimated the yield of the test at 13 kilotons back in 2013. However, the yield has been revised to 5.4 kilotons.
12 February 2013: The test possible took place in the West Tunnel. The Federal Institute for Geosciences and Natural Resources estimated the yield at 40 kilotons back in 2013; however, the yield has since been revised to 14 kilotons.
6 January 2016: The testing was claimed to be of a hydrogen bomb. The Federal Institute for Geosciences and Natural Resources originally estimated the yield as 14 kilotons but has since revised to 10 kilotons.
9 September 2016: North Korea announced that this is a successful test of a warhead that can be mounted onto a rocket. Siegfried S. Hecker, former director of the Los Alamos National Laboratory, estimated yield at 15 to 25 kilotons. The Federal Institute for Geosciences and Natural Resources has initially estimated the yield as 25 kilotons.