North Korea seen readying for fourth nuclear test - report

SEOUL (Reuters) - Activity in North Korea appears to show it is preparing for a fourth nuclear test, with movement at its atomic test site similar to events preceding earlier blasts, a newspaper reported on Monday, quoting a senior South Korean government official.

North Korea has intensified warnings in recent weeks, declaring it had entered a state of war with Seoul, threatening to strike U.S. targets and blocking access to a border factory complex jointly run with the South.