TOKYO - North Korea appears to have conducted a nuclear weapons test early Friday, the Yonhap News Agency reported.
If confirmed, it would be North Korea’s fifth nuclear weapons test since 2006, all in violation of UN resolutions.
South Korea’s military reported that a magnitude 5 earthquake was detected early Friday near the Punggye-ri nuclear test site in northeastern North Korea.
"An artificial quake was detected near North Korea's Punggye-ri at around 9:30 a.m.," South Korea's Joint Chiefs of Staff said, according to Yonhap.
The blast is being monitored by U.S. agencies.
"We are aware of seismic activity on the Korean Peninsula in the vicinity of a known North Korean nuclear test site. We are monitoring and continuing to assess the situation in close coordination with our regional partners," Ned Price, spokesperson for the National Security Council in Washington, DC, said in a prepared statement.
Friday marks the 68th anniversary of the founding of the Democratic People’s Republic of North Korea. In the past, the reclusive nation has marked major anniversaries with weapons tests or other provocative actions.
About 28,000 U.S. troops are stationed in South Korea, which technically remains at war with its neighbors to the north.
In January, North Korea conducted what it said was a test of a hydrogen bomb, and has conducted several tests of medium- and long-range missiles since, part of its push for a nuclear-armed missile that could one day reach the U.S. mainland.
Earlier this week, North Korea fired three ballistic missiles into Japan’s exclusive economic zone in the Sea of Japan in an apparent signal of its displeasure with G-20 talks being held in Hangzhou, China.
European and U.S. monitoring services also detected similar seismic activity, with the U.S. Geological Survey calling it an "explosion" on its website.