North Korea conducts third nuclear test, drawing new sanctions threat

SEOUL (Reuters) - North Korea conducted its third nuclear test on Tuesday in defiance of existing U.N. resolutions, angering the United States and Japan and prompting its only major ally, China, to call for calm.

The North said the test had "greater explosive force" than the 2006 and 2009 tests that were widely seen as small-scale. Its KCNA news agency said it had used a "miniaturized" and lighter nuclear device, indicating that it had again used plutonium which is more suitable for use as a missile warhead.