North Korea carries out apparent nuclear test

Security Council diplomat says the apparent test comes despite a "strong warning" from China to the North.

SEOUL/ UNITED NATIONS: North Korea staged an apparent nuclear test of six to seven kilotons Tuesday in a striking act of defiance that, if confirmed, is sure to trigger global condemnation from enemies and allies alike.

Seismic readings from the area around North Korea's nuclear test site detected a "suspected explosion", according to China's Earthquake Administration, and South Korea said all the signs pointed to a test.

"We suspect North Korea has pushed through with a third nuclear test," South Korean defence ministry spokesman Kim Min-Seok told reporters, putting the yield at significantly more than North Korea's two previous tests in 2006 and 2009.

North Korea had provided China and the United States with advance warning that a test was imminent, Kim said, after the communist state earlier Tuesday called for "high-intensity" action and further long-range rocket launches.

In Vienna, the Comprehensive Nuclear Test Ban Treaty Organisation said the location of Tuesday's explosion was "roughly congruent" with the 2006 and 2009 tests, and labelled the event a "clear threat" to international peace.

The two previous tests triggered waves of UN sanctions, and the Security Council was set to meet in emergency session on Tuesday morning in New York in response to the apparent third detonation.

The response of China, North Korea's economic and diplomatic patron, will be key. While restraining US-led allies from stronger action against Pyongyang in the past, Beijing had pressed the country to hold off on the third test.

The apparent test came despite a "strong warning" from China to the North, a Security Council diplomat said.

For nuclear experts, the key question will be whether North Korea used up more of its scarce reserves of plutonium for the suspected third test, or used uranium in a new and self-sustaining path to atomic detonations.

The South Korean defence ministry spokesman said it was unclear yet whether uranium was used.

Regional seismic monitoring agencies detected a seismic event, of a magnitude between 4.9 and 5.1, at 11:57 am local time with the epicentre in the same location as the North's Punggye-ri nuclear test site.

The explosive yield estimated by Seoul's defence ministry compared with 15 kilotons in the world's first atomic bomb dropped by the United States on the Japanese city of Hiroshima in 1945.

UN Security Council to meet

The UN Security Council will hold an emergency meeting on North Korea's apparent nuclear test at 9:00 am local time on Tuesday, council diplomats said.

Diplomats had said previously that the United States, South Korea and European members would want the Security Council to adopt a resolution that would impose new sanctions on Pyongyang in the event of a third nuclear test in defiance of earlier council resolutions.

Getting approval on a council resolution, however, could take weeks.