UPDATE: 5:46 a.m. EST — Japan’s defense ministry has deployed three T4 training planes to collect possible radioactive material in the air following North Korea’s claimed hydrogen bomb test, Agence France-Presse reported, citing officials.

The cabinet ministry earlier said that no abnormal levels of nuclear radiation have so far been detected across Japan. “To understand the impact of possible radioactive materials released by the test, Air Self-Defense Force planes have collected dust in the air,” Chief Cabinet Secretary Yoshihide Suga, the government’s top spokesman, said, at a press conference. “It is currently being sent to the Japan Chemical Analysis Center.”

UPDATE: 4:05 a.m. EST -- South Korea's spy agency told lawmakers Wednesday that North Korea may have tested an atomic bomb and not a hydrogen bomb, the Associated Press reported.

Meanwhile, China’s foreign ministry said that it will carry out emergency radiation tests in border areas after North Korea's announcement, the People’s Daily reported.

Beijing said it “firmly” opposed Pyongyang’s actions, with spokeswoman Hua Chunying calling on the reclusive nation to “stop taking any actions which would worsen the situation on the Korean peninsula.”

UPDATE: 2:44 a.m. EST -- The South Korean meteorological administration said Wednesday that weather patterns are unlikely to spread radioactivity in South Korea after Pyongyang's alleged nuclear test, Yonhap News Agency reported.

Ko Yun-hwa, the chief of the meteorological administration, said in a press briefing, that if radioactive substances were created, it would most likely be filtered into the East Sea, also known as the Sea of Japan.

Japan's Nuclear Regulation Authority said it will conduct a media briefing Wednesday on estimates of the impact of any radiation from the test, Reuters reported.

UPDATE: 1:27 a.m. EST -- South Korea's defense ministry said Wednesday that a small amount of hydrogen may have been added to a device North Korea tested earlier in the day, claiming it to be a hydrogen bomb, Reuters reported, citing local media reports.

The comments come after South Korean intelligence officials raised doubts over Pyongyang’s claims of successfully testing its first hydrogen bomb.

"We will find out after closely analyzing it but we understand a small amount of hydrogen may have been added to the fourth nuclear test," ministry spokesman Kim Min-seok told reporters.

UPDATE: 12: 43 a.m. EST -- South Korea's intelligence agency said Wednesday that the device North Korea tested may not have been a hydrogen bomb, Reuters reported, citing South Korea’s Yonhap News Agency.

South Korea's meteorological agency, which recorded a 5.1-magnitude earthquake before the announcement by Pyongyang, said that it had not detected any radiation after the test. North Korea announced earlier Wednesday that it had successfully conducted a nuclear test, but outside experts are yet to confirm the test.

If confirmed, this would be the first time that North Korea would have tested a hydrogen bomb.

UPDATE: 12:05 a.m. EST -- The U.N. Comprehensive Test Ban Treaty Organization, which monitors nuclear testing worldwide, reacted to North Korea’s hydrogen bomb test Wednesday, stating that, if confirmed, Pyongyang’s latest move would be a breach of the treaty and a grave threat to international peace and security, according to the Associated Press.

Lassina Zerbo, head of the watchdog organization, reportedly urged North Korea to refrain from any further nuclear testing activities and join the 183 countries that have joined the treaty since 1996.

Sen. Tom Cotton (R-Arkansas) also released a statement over the nuclear test. “This is the latest and most brazen in a long line of ‎provocations from the tyrannical Kim regime. Such behavior is wholly unacceptable. In the near term, the U.S. must lead with a firm response, including an enhancement of sanctions that targets the financial resources of the regime that fund its misrule and nuclear proliferation,” Cotton said. 

“We must recognize the parallels between North Korea’s nuclear ambitions and Iran’s. The path to what is now the fourth North Korean nuclear test ‎began two decades ago with a weak and unverifiable deal negotiated by a naive U.S. president. We now must take up the hard work of pressuring and deterring a maniacal nuclear-capable regime.”

The U.N. Security Council is planning to hold a security meeting Wednesday to discuss North Korea’s latest move, three council diplomats, who spoke on the condition of anonymity, told Reuters, adding that the emergency meeting would probably take place at 11 a.m. EST.

UPDATE: 11: 51 p.m. EST -- The White House said that it could take several days to determine if North Korea’s move to test a hydrogen bomb was successful. Pyongyang has claimed its test was a success.

The Obama administration said that it is “monitoring and continuing to assess the situation” with regional partners, and also said that it condemned any violation of the U.N. Security Council resolutions.

Meanwhile, U.S. Republican presidential candidate Sen. Marco Rubio of Florida condemned the test by calling North Korean leader Kim Jong un a “lunatic.”

“I have been warning throughout this campaign that North Korea is run by a lunatic who has been expanding his nuclear arsenal while President Obama has stood idly by. If this test is confirmed, it will be just the latest example of the failed Obama-Clinton foreign policy.” Rubio said, in a statement.

“Our enemies around the world are taking advantage of Obama’s weakness. We need new leadership that will stand up to people like Kim Jong-un and ensure our country has the capabilities necessary to keep America safe.”

UPDATE: 11:30 p.m. EST – South Korea’s defense ministry said Wednesday that the country’s armed forces will beef up its monitoring of North Korea after Pyongyang successfully tested a hydrogen nuclear bomb Wednesday, Reuters reported.

UPDATE: 11:16 p.m. EST -- North Korea said Wednesday that it tested the hydrogen bomb to assert its right to “self defense” against the United States and other enemies, reports said.

North Korea also promised it would act as a responsible nuclear state and vowed not to use its nuclear weapons if the international community respects its sovereignty, Reuters reported. 

Meanwhile, Japanese Prime Minister Shinzo Abe condemned the nuclear test saying that his country "absolutely cannot tolerate" a North Korean nuclear test. Abe reportedly called the test a threat to its security, adding that Japan will make a firm response to North Korea's move.

Pyongyang also reportedly said that it would continue to strengthen its nuclear program in order to protect itself against the hostile policies of the United States.

Original story:

North Korea has successfully conducted a hydrogen bomb test, the country reportedly announced Wednesday.

The announcement came hours after South Korea’s meteorological service detected a 5.1-magnitude “artificial earthquake” near Pyongyang’s main nuclear test site.

China, Japan and South Korea earlier said that there were indications the tremor was man-made, suspecting that North Korea may have carried out a new nuclear test.

The tremor originated about 30 miles north of Kilju, in country's northeast where North Korea's main nuclear test site is located.