Seoul (AsiaNews/Agencies) – Pyongyang has staged a "successful" underground nuclear test, the state-run Korean Central News Agency KCNA reports, adding that today’s test was more powerful than the previous one in October 2006. The United Nations Security Council has called an emergency meeting, while international diplomats have expressed “concern” and the Asian stock exchange plummeted: Seoul lost 6.3%, before closing at minus 1.4%.

An official statement released by KCNA reads “The Democratic People's Republic of Korea successfully conducted one more underground nuclear test as part of the measures to bolster up its nuclear deterrent for self-defence”.

South Korean officials reported that a seismic tremor was detected in the north-eastern part around the town of Kilju - the site of North Korea's first nuclear test. Both South Korea's and the US geological agencies said the tremor indicated a nuclear explosion.  The US Geological Survey said the 4.7-magnitude quake was detected at 9.54 (local time). It happened 10km (six miles) below the surface. Hours after the nuclear test North Korea also test-fired a short range missile.  

Pyongyang’s latest challenge further heightens tensions with the International community already strained by the missile experiment of April last and its decision to abandon the six party nuclear talks.  Russia's U.N. ambassador Vitaly Churkin has called an emergency summit of the Security Council.  The European Union speaks of “very worrying” developments, US President Barak Obama has condemned the latest developments saying they “constitute a threat to international peace and security“.  Kazuo Kodama, spokesperson for the Japanese Foreign Minister says Japan will respond “in an adequate manner” to the North Korean Nuclear challenge; the South Korean President Lee Myung-bak has called an emergency cabinet meeting, even though the people are still shaken by the suicide of former president Roh Moo-hyun, May 23rd last.

The nuclear test has also had serious consequences on the stock markets in Asia.  In Seoul the Kospi index fell to minus 6.3% before closing at minus 1.4%. Hong Kong slid to 0.3%; China and Australia also closed in with negative loses.  Only Tokyo closed in the positive with 1.3%.