After six underground nuclear tests conducted at Punggye-ri site, the Democratic People's Republic of Korea (DPRK) dismantled the nuclear test site on May 24. Read further to understand more about the Punggye-ri nuclear test site and the six underground nuclear tests conducted there.

　　A satellite photo of the Punggye-ri nuclear test site in DPRK, May 14, 2018. [File photo: VCG]

　　The Punggye-ri Nuclear Test Site

　　Punggye-ri is a village located in Kilju County, North Hamgyong Province, DPRK. The Punggye-ri Nuclear Test Site is located nearby.

　　Situated in mountainous terrain in the northeast of the country, the Punggye-ri Nuclear Test Site is the only known nuclear test site in DPRK. It is thought to be the only active nuclear test site in the world.

　　The nuclear tests have taken place in a system of tunnels dug below Mount Mantap, near the Punggye-ri site. All of the tests have been conducted underground at the Punggye-ri site.

　　People gather at the Main Support Area at the Punggye-ri nuclear test site in DPRK, August 4, 2016. [File photo: VCG]

　　The six underground nuclear tests conducted at Punggye-ri site

　　Nuclear tests were conducted at the site in October 2006, May 2009, February 2013, January 2016, September 2016, and September 2017.

　　October 9, 2006 -- The official KCNA news agency reports that DPRK conducted a successful nuclear test in North Hamgyong province in the country's northeast. The UN Security Council on October 14 passes Resolution 1718 to condemn the test.

　　May 25, 2009 -- The DPRK conducts its second nuclear test. The KCNA says that DPRK scientists have been able to increase the explosive power and control level of the bomb compared with the first test. The test prompts UN Security Council Resolution 1874, which voices "the strongest condemnation" against DPRK authorities and demands the country stop further nuclear weapons-related activities.

　　Probable cabling and water drainage seen at the North Portal of the Punggye-ri nuclear test site in DPRK, March 25, 2017. [File photo: VCG]

　　February 12, 2013 -- DPRK carries out a third nuclear test, which KCNA describes as "high level, safe and perfect." the Republic of Korea (ROK) estimates the bomb has a power equal to 6,000-7,000 tons of TNT. The UN Security Council unanimously passes Resolution 2094 on March 7, demanding the DPRK give up its nuclear weapons project and return to the Nuclear Non-Proliferation Treaty.

　　January 6, 2016 -- KCNA announces DPRK has carried out its fourth nuclear test, claiming it is a successful test of its first hydrogen bomb. The test means that the DPRK has "proudly joined the advanced ranks of nuclear weapons states possessing the H-bomb," said KCNA.

　　September 9 , 2016 -- DPRK announced its fifth nuclear test in 2016 in September. Estimates of the explosive yield have varied. ROK's military said it was about 10 kilotons but other experts say initial indications suggest 20 kilotons or more.

　　September 3, 2017 -- DPRK claimed it has successfully tested what the world has worried about - a miniaturised hydrogen bomb that could be loaded on to a long-range missile. Seismic readings of 6.3 on the Richter Scale indicates the test was bigger than any other DPRK has conducted. Some early estimates said that the test came in at about 100-150 kilotons, potentially 10 times larger than the previous test. The official KCNA news agency describes the test as a "perfect success" and a "very meaningful step in completing the national nuclear weapons program."