November 10, 2009 - North Korean ship reportedly suffers heavy damage as each side blames the other for violating disputed sea border (by Tania Branigan for guardian.co.uk).

Ships from the North and South Korean navies exchanged fire off the peninsula's west coast today, with each side blaming the other for violating the disputed sea border.

The clash was the first of its kind for seven years. Seoul said there were no casualties on its side and it is unclear if there were deaths on the North Korean vessel – suggesting this was less serious than the deadly naval skirmishes of 1999 and 2002.

North Korea has launched three short-range missiles this morning, just after an underground nuclear test.

Pyongyang announced this morning having conducted a successful underground nuclear test, more powerful than the previous 2006 test which had led to international sanctions.

The test was immediately followed by the launch of three short-range missiles in less than 12 hours, leading the Security Council of United Nations to call for an emergency meeting today.

The first reports from Seoul suggest that the test was conducted about 15 kilometers from the first North Korean test center in the town of Kilju (North Hamgyong province), in the northwest of the country.

The previous nuclear test in 2006 had a power estimated between 5 and 15 kilotons, while the test made today has reached 20 kilotons which, according to Russian experts, exceeds the North Korean capacity of technical control.