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South Korean and US troops placed on high alert

South Korean and US troops boosted their alert level to the highest category since 2006 today, after the North threatened military strikes on allied military forces in escalating tensions over its nuclear test.

North Korea yesterday threatened war if there were any attempts to search its ships for weapons of mass destruction, and renounced the 1953 truce that ended the Korean War, raising the prospect of a naval clash off the Korean peninsula's west coast.

The move by the South Korea-US combined forces command increased the surveillance to level 2 from the present level 3, Won Tae-jae, a Defence Ministry spokesman, said. He said that was the highest level since 2006, when the North conducted its first-ever nuclear test.

The US has 28,500 troops in South Korea as a deterrent against North Korea.

The already high tension in the region has been ratcheted up still further since North Korea carried out an underground test of a nuclear bomb on Monday.

Pyongyang's warning came in response to an announcement by South Korea that it would join a US led anti-proliferation programme aimed at stopping and inspecting ships suspected of transporting banned weapon, including nuclear technology.

Mr Won said the raised alert level meant more aviation surveillance assets, intelligence analysts and other intelligence-collecting measures would be deployed to watch North Korea. He refused to disclose further details.

The North repeatedly warned that it would consider the South's participation in the US-led Proliferation Security Initiative as a declaration of war against North Korea.

The North would "deal a decisive and merciless retaliatory blow to anyone trying to inspect its vessels," said a statement by the Korean People's Army yesterday.

Key world powers, meanwhile, have proposed a range of expanded UN sanctions against North Korea in response to its nuclear test as well as measures to give teeth to existing bans and ship searches against the reclusive country, a UN diplomat said yesterday.

The five permanent veto-wielding council members — the United States, Russia, China, Britain and France — and the two countries most closely affected by the nuclear test — Japan and South Korea — discussed possible UN sanctions and other measures for a new Security Council resolution on Tuesday.

The diplomat, who is familiar with the talks but spoke on condition of anonymity because they were closed, said there was a clear commitment to go for sanctions in the new resolution and no reluctance from North Korea's allies, China and Russia. But what measures the 15-member council ultimately agrees to remains to be seen.

Hillary Clinton, the US Secretary of State, also said North Korea faced consequences for its nuclear and missile tests and denounced its "provocative and belligerent" threats. She underscored the firmness of the US treaty commitment to defend South Korea and Japan, which are in easy range of North Korean missiles.

From May 28, 2009