Troops on Higher Alert in South Korea

The South Korean and U.S. militaries were placed on heightened levels of alert and surveillance on Thursday, one day after North Korea threatened the South with a possible military attack.

The allied troops, including 28,000 U.S. Soldiers based in South Korea, raised their Watch Condition, or Watchcon, to the second- highest level, the South Korean Defense Ministry announced.

South Korea has put its military on this high an alert level only five times since the three-year Korean War ended in a cease-fire in 1953, most recently after North Korea conducted its first nuclear test in October 2006.

Meanwhile, the North's state-controlled media kept up its harsh rhetoric, warning Thursday that "even a minor accidental clash could lead to nuclear war."

"It's just a matter of time before a fuse of war is lit," the North Korean government's official newspaper, Minju Joseon, said in a commentary carried by its state-run news agency, KCNA.

While the South Korean government urged its people to remain calm, there was no sign of anxiety among villagers along the border. In Seoul, the South Korean capital, just 56 kilometers, or 35 miles, from the border and within the range of North Korean missiles and artillery, government officials and citizens prepared for the funeral on Friday of former President Roh Moo-hyun, who committed suicide last weekend.

The Defense Ministry declined to confirm South Korean news reports that its military had moved, or planned to move, more naval ships and artillery pieces to islands near the western sea border with North Korea. But a South Korean military official said that in recent months North Korea had increased training of its coastal artillery crews opposite the South Korean islands.

The change from Watchcon 3 to Watchcon 2 involves a significant increase in the use of reconnaissance planes and spy satellites, as well as more vigorous collection and analysis of electronic signals from the North, ministry officials said.

Watchcon 2 status is taken when the militaries fear "a grave threat," the officials said.

North Korea had stepped up its threats against South Korea and the United States on Wednesday with warnings of a "powerful military strike" if any North Korean ships were stopped or searched as part of an American-led operation to intercept vessels suspected of carrying unconventional weapons.

South Korea had agreed to join the operation after North Korea conducted its second-ever nuclear test on Monday. Earlier the North had warned the South not to participate in the operation, known as the Proliferation Security Initiative, saying it would constitute an act of war.

In its statement on Wednesday, North Korea also said it "no longer feels bound by the armistice" that ended fighting in the Korean War. Technically, the two Koreas have remained at war, because the 1953 armistice was never replaced with a peace treaty.

Washington and Seoul consider such North Korean statements as attempts to raise tensions and draw the United States into bilateral talks.

"The armistice remains in force and is binding on all signatories, including North Korea," said a statement from the American-led United Nations Command, a signatory to the 1953 armistice.

North Korea's nuclear test, which was followed by the test- firings of several short-range missiles, drew swift condemnation worldwide.

"North Korea continues to act in a provocative and belligerent manner toward its neighbors," said Secretary of State Hillary Rodham Clinton. "There are consequences to such actions."

At the United Nations, she said, discussions were under way "to add to the consequences North Korea will face."

American and Japanese diplomats were drafting a Security Council resolution that would focus on five or six ways to flesh out existing sanctions against North Korea that had never been enforced, diplomats said. While China supports the idea of sanctions, it wants to bolster measures first passed in 2006 rather than create new ones, they said.

The proposals include banning imports and exports of all arms; only heavy weapons are restricted now. "We want to dry out their resources for the military," said a senior Western diplomat, speaking anonymously because of the sensitivity of the negotiations.

North Korea has said that it would consider further sanctions a declaration of war.

In interviews in recent weeks, analysts at government-run and private policy institutes in South Korea have said that if South Korea joined the global interdiction program, the chances of a North Korean provocation would increase. But they added that any clash between the countries would probably be a limited one.