A magnitude-6.3 seismic event was recorded in North Korea Sunday that the U.S. Geological Survey says was a “possible explosion, located near the site where North Korea has detonated nuclear explosions in the past.”
South Korea’s Korea Meteorological Agency said it is suspected to be an “artificial earthquake.”
Some past seismic events in North Korea have been caused by nuclear tests. North Korea has conducted five nuclear tests since 2006, including two last year, which have sparked international condemnation.
A South Korean military official told NBC News that “we suspect that the artificial earthquake … to be the 6th nuclear test.”
The event was recorded around 13 miles northeast of Sungjibaegam just after 12:30 p.m. Seoul time (11:30 p.m. Saturday ET), the USGS said. The event was initially reported as a magnitude-5.1 event. The USGS later said it was a magnitude-6.3 event.
Earlier Sunday, North Korea’s state news agency KCNA claimed that country has developed a “more developed” nuclear weapon it called a hydrogen bomb, a boast that follows intercontinental ballistic missile tests.
South Korea’s president is expected to hold an emergency National Security Council meeting Sunday, a presidential spokesperson said.
North Korea in July conducted two intercontinental ballistic missile tests, and experts said the tests indicated the missiles could reach parts of the United States. After the ICBM tests, the United Nations imposed tough new sanctions on North Korea that included a ban coal and other exports worth over $1 billion.