Photos show new N. Korea nuclear test tunnel: US think tank

Recent satellite imagery suggests North Korea is excavating a new tunnel at its main nuclear test site, although there are no indications that a test in imminent, a US think tank said Thursday.

The tunnel is in a new area of the Punggye-ri site, separate from three other tunnels that the North has excavated or used for actual tests in the post, the US-Korea Institute at Johns Hopkins University said.