An undated file photo shows North Korean leader Kim Jong-Un inspecting a test-fire of strategic submarine-launched ballistic missile

Seoul: North Korea said it has carried out a successful "nuclear warhead explosion" test to counter what it called US hostility, North Korean state TV reported, angering neighbours and the United States. This is the fifth nuclear test — second in eight months — that has been carried out by North Korea and drew immediate condemnation from the South, which said the "maniacal recklessness" of young ruler Kim Jong-Un would lead to "self-destruction".