North Korea Claims To Have Carried Out Nuclear Test

North Korea's official news agency says the country has successfully carried out an underground nuclear test. It says there has been no leak or danger, but has as yet given no details about the location or size of the test. The United States Geological Survey says it has detected no seismic activity on the Korean peninsula in the past 48 hours.However, South Korea says it detected an explosion in the north. The region has been on high alert since North Korea said last week it would conduct a nuclear test. Earlier, South Korean news agency Yonhap says the South Korean president called an emergency meeting to discuss the issue. A foreign ministry spokesman told the news agency there had been a grave change in the situation involving the North's nuclear activity.Japan's Prime Minister Shinzo Abe has just arrived in Seoul for a meeting with Mr Roh, following talks on the crisis with his Chinese counterparts in Beijing. At the Beijing summit, Japanese and Chinese leaders said that such a test would be considered "unacceptable".