North Korea said today it will close its land border with the South from next month, largely putting a stop to the few exchanges that exist between the states divided since the Cold War.
The move follows growing anger in Pyongyang at the hardline approach of the South's conservative government over its nuclear weapons programme. It accused its wealthy neighbour of taking their confrontation "beyond the danger level".
The little traffic there is across their heavily armed border is the product of agreements during 10 years of left-leaning leaders in Seoul.
Relations between the states have increasingly frayed since February, when conservative President Lee Myung-bak took office pledging to get tough with Pyongyang but offering massive economic aid if it mended its ways.
Last month, North Korea threatened to reduce the South to rubble unless it stopped civic groups from sending anti-Pyongyang leaflets into the communist state. Analysts say the recent flood of such leaflets had rattled the North's leaders.
"The leaflets are going deeper into the country than before and this has increased concern in North Korea, especially because it comes at a time when there is speculation on (leader) Kim Jong-il's health," one South Korean government source said.
There have been widespread reports that Kim, who heads the world's first communist dynasty, may have suffered a serious stroke, although the North has insisted he is in good health and still firmly in charge.
The North says agreements reached over the previous 10 years were being flouted since Mr Lee took office. North Korea's KCNA news agency said the border closure would take effect from December 1st.
"The South Korean puppet authorities should never forget that the present inter-Korean relations are at the crucial crossroads of existence and total severance," it said.
A Unification Ministry official in Seoul said it was not clear whether the North meant to close the border completely. "We don't think it means complete closure," he said.
There are two main road crossings over the demilitarised zone that has divided the peninsula since the end of the 1950-53 Korean War, for which a peace treaty has never been agreed.
One leads to the the Kaesong industrial park, operated by the South just across the border and the one tangible commercial link between the two, and takes tour groups on to nearby Kaesong city.
The other is on the east side of the peninsula to another tour site, Mt Kumgang. That site was closed to tourists earlier this year after a South Korean tourist was shot dead.
A rail link was opened for regular runs last December for the first time in almost 50 years but it carries almost no cargo.
The North is likely to be further irritated by a decision by South Korea's human rights agency, announced yesterday, to set up a committee to look at abuses in the North.
Reuters