SEOUL, Sept. 9 (Xinhua) -- The Democratic People's Republic of Korea (DPRK) appeared to have conducted its fifth nuclear test after an artificial earthquake was detected at a site where its fourth nuclear test was carried out earlier this year, Yonhap news agency reported on Friday.
South Korea's Joint Chiefs of Staff (JCS) was quoted as saying that artificial earthquake waves of magnitude 5.0 were detected at about 9:30 a.m. local time (0030 GMT) at the DPRK's main Punggye-ri nuclear test site. The JCS is analyzing the details.
The European Mediterranean Seismological Centre upgraded the artificial quake's magnitude from an initial 5.0 to 5.3. The U.S. Geological Survey saw the tremor as a 5.3-magnitude quake.
The U.S. monitoring agency said the magnitude was caused by an explosion, but it said it could not determine what type of explosion it may be.
A 5.0-magnitude artificial earthquake was recorded before Pyongyang's fourth nuclear test on Jan. 6 at Punggye-ri where all of the four DPRK underground nuclear tests had been carried out since 2006.
An unnamed government source was quoted as saying that the DPRK may have conducted another nuclear test to mark the country's National Day. The source said a nuclear test is highly likely in consideration of the detected site and magnitude.
According to media reports, Pyongyang had been preparing for its fifth nuclear test ahead of the 68th birthday of the nation on Sept. 9.
If confirmed, it would mark the fifth nuclear detonation by the DPRK following the first in October 2006, the second in May 2009, the third in February 2013 and the fourth in January this year.
Prime Minister Hwang Kyo-ahn called an emergency meeting of the National Security Council (NSC) following the suspected test, the presidential office Cheong Wa Dae said. President Park Geun-hye is on her overseas trip to Laos.
Pyongyang has conducted a series of ballistic missile launches since top DPRK leader Kim Jong Un gave an order on March 15 to test a nuclear warhead and ballistic rockets capable of carrying the warhead "in a short time."
