N. Korea carries out 'biggest ever' nuclear test: Seoul

North Korea is believed to have conducted a fifth nuclear test, its most powerful to date, South Korea's military said Friday after monitors detected a 5.3-magnitude "artificial earthquake" near its main nuclear site. A confirmed test by the isolated North would send tensions soaring over its nuclear and ballistic missile ambitions, which have already earned international condemnation and United Nations sanctions. The quake was detected near North Korea's Punggye-ri nuclear test site as the coun