A 5.1 magnitude earthquake has been registered in North Korea near a former nuclear testing site, and North Korea claims it was caused by the detonation of a hydrogen bomb test.
The tremor was confirmed about 19 kilometres from the town of Sungjibaegam by the U.S. Geographical Society, and the Democratic People's Republic of Korea released a bizarre statement saying a successful test had occurred.
"Through the test conducted with indigenous wisdom, technology and efforts the DPRK fully proved that the technological specifications of the newly developed H-bomb for the purpose of test were accurate and scientifically verified the power of smaller H-bomb," the statement read.
"The test means a higher stage of the DPRK's development of nuclear force.
"By succeeding in the H-bomb test in the most perfect manner to be specially recorded in history the DPRK proudly joined the advanced ranks of nuclear weapons states possessed of even H-bomb and the Korean people came to demonstrate the spirit of the dignified nation equipped with the most powerful nuclear deterrent."
A hydrogen bomb has never been used in warfare but one was detonated in a test by the U.S. at the Bikini Atoll in the Pacific in 1956. A hydrogen bomb is considered to be more powerful than atomic bombs, which were dropped on Japan at the close of World War II.
Japan Prime Minister Shinzo Abe on Wednesday denounced the test.
“A nuclear test by North Korea poses a major threat to our national security," Abe said at a nationally televised press conference.
"It cannot be acceptable. We strongly denounce it.”
Foreign minister Julie Bishop strongly condemned the test as flying in the face of international non-proliferation norms, and said Australia will intensify its counter-proliferation cooperation with partners to strengthen sanctions, with the aiming of reducing the funding of North Korea’s WMD programs.
"Australia will make our concerns known to the North Korean Government directly, as well as in international and regional forums," she said in a statement.
"We call on international bodies, including the UN Security Council, to provide a strong response to North Korea’s actions.
"Australia will continue to work with our friends and partners to support the security of the Republic of Korea and the stability of our region."
Yesterday the Korean Central News Agency released a statement citing the U.S. use of nuclear bombs in WWII as a reason why the nation was "a hideous nuclear criminal nation that has constantly posed nuclear blackmail for more than 70 years, seriously endangering mankind".
The statement also had a warning to the U.S. to stop "foolish moves" that could provoke nuclear war.
"It is quite natural that the DPRK had an access to nuclear weapons and codified it and has steadily bolstered them under the new line of simultaneously pushing forward economic construction and the building of nuclear force in order to repel the U.S. nuclear blackmail.
"The U.S. increased nuclear threats are a basic factor that compelled the DPRK into bolstering a nuclear deterrence.
"The U.S. had better face up to the situation and stop at once the foolish moves for provoking a nuclear war."
South Korea's presidential office has reportedly convened an emergency security meeting while Japan's chief government spokesman said the earthquake was likely caused by a nuclear test.
The U.S. Defense Department said it is "looking into reports of a possible seismic event near North Korea's nuclear facilities."
University of Adelaide international politics associate professor Felix Patrikeeff has been studying North Korea for many years and said the test was not unsurprising.
“It’s a characteristic of the North Korea regime that time after time they go to the very edge in terms of surprising world powers,” Patrikeeff said.
“The North Korea regime said a little while ago that it was planning on testing a hydrogen bomb and at first glance, it appears this is what has come to pass.”
South Korean stocks and the won currency fell slightly after reports of the likely test on Wednesday.