N Korea 'prepares for nuclear test'
North Korea is digging a new underground tunnel in what appears to be preparation for a third nuclear test, according to South Korea.
A report written by intelligence officials says recent satellite photos show piles of dirt near the newly excavated tunnel's entrance.
The report says the excavation at the North's north-east Punggye-ri site is in its final stages. Experts say dirt is needed to fill up underground tunnels before a nuclear test.
The report's release comes as North Korea prepares to fire a long-range rocket between April 12 and 16 that Washington and others say is a cover for testing missile technology that could be used to fire on the United States.