South Korean and US troops facing North Korea boosted their alert level Thursday to the highest category since 2006, after the communist regime threatened military strikes on allied troops in escalating tensions over its nuclear test.
North Korea threatened Wednesday to attack any US and South Korean ships that try to intercept its vessels and renounced a 1953 truce halting the Korean War fighting, raising the prospect of a naval clash off the Korean peninsula's west coast.
The North was responding to Seoul's decision to join a US-led anti-proliferation program aimed at stopping and inspecting ships suspected of transporting banned weapons, including nuclear technology. South Korea announced it was joining after the North's underground test blast of a nuclear bomb.
On Thursday, the South Korea-US combined forces command increased the surveillance to level 2 from the present level 3, Defense Ministry spokesman Won Tae-jae said. He said that was the highest level since 2006, when the North conducted its first-ever nuclear test.