There is a growing concern that North Korea might be preparing to test a nuclear bomb. On July 5, the country test-fired seven missiles into the Sea of Japan, prompting a United Nations Security Council resolution, which condemned the country and banned U.N. member states from transferring missile-related technology and materials to it. A nuclear explosion would have much more serious consequences and further push North Korea into isolation.

The concern was touched off by an Aug. 17 report by America's ABC News. It quoted a senior military official as saying that a U.S. intelligence agency had observed suspicious vehicle movement at a suspected North Korean underground nuclear test facility called Pungyee Yok in northeast North Korea. After the report, Japan's Foreign Ministry said that it had boosted surveillance of the area and would carefully analyze intelligence.

Mr. Kim Seung Kyu, director of South Korea's National Intelligence Service, was quoted as saying in a closed-door briefing to the National Assembly that North Korea is capable of conducing an underground nuclear-bomb test, although his agency has not yet detected evidence that the North is preparing for a test. South Korean Defense Minister Yoon Kwang Ung told a parliamentary meeting that North Korea is estimated to have one or two nuclear weapons. North Korea itself claims to have nuclear weapons, but it has not yet carried out any known nuclear explosion.