N Korea 'not bound by armistice'

North Korea has declared an end to its half-century-old armistice with the South, saying that it sees Seoul's move to join a US-led anti-proliferation initiative as a "declaration of war".The warning carried on state media on Wednesday comes two days after North Korea conducted a second nuclear test and also follows a series of missile launches.The announcement also came amid reports in South Korean media that the North had restarted its main plutonium producing nuclear reactor at Yongbyon.The reactor had previously been mothballed under a six-nation aid for disarmament deal, but in April the North said it had scrapped the agreement and would resume work on building nuclear weapons.Following the Monday's nuclear test South Korea announced it would become a full member of the Proliferation Security Initiative (PSI), a US-led drive to curb trade in weapons of mass destruction.It said the decision had already been taken following the North's controversial April 2 rocket launch, although the formal announcement was brought forward following the nuclear test.