PYONGYANG, North Korea, Jan. 5 (UPI) -- The North Korean government said it has successfully tested a hydrogen bomb, setting the region on alert and setting off a tremor in the area of its test site.
North Korean state media made the announcement early Wednesday after seismic monitors detected a 5.1 earthquake near the Punggye-ri test site. The first such weapon developed by the regime, if confirmed, would be a significant step up in North Korea's military ability, because hydrogen bombs are far more powerful than plutonium-based atomic weapons.
The country has likely conducted three previous underground plutonium-based nuclear tests since 2006.
"If there's no invasion on our sovereignty we will not use nuclear weapon," the North Korean state news agency said. "This H-bomb test brings us to a higher level of nuclear power."
Last month international experts were skeptical when North Korean dictator Kim Jong Un said his government had developed a hydrogen bomb.
Experts said it would take several days to determine if the tests were real and successful. Meanwhile, government in the region as well as the United Nations Security Council are holding emergency meetings.
Japanese Prime Minister Shinzo Abe condemned the test, declaring it a "serious threat" to his country's security.
"It clearly violates the UNSC resolution and is a serious challenge to the nuclear non-proliferation efforts," Abe said.
But North Korea's claims could just be its latest exaggerations.
"North Korea appears to have had a difficult time mastering even the basics of a fission weapon," said Bruce Bennett, senior defense analyst at the nonpartisan Rand Corp. "This suggests that unless North Korea has had help from outside experts, it is unlikely that it has really achieved a hydrogen/fusion bomb since its last nuclear test, just short of three years ago."