Satellite images show that North Korea may have resumed tunnel excavation at its main nuclear test site, similar to activity seen before the country's most recent nuclear test in January, a U.S. North Korea monitoring website reported Wednesday.
The 38 North website, run by the Johns Hopkins University's School of Advanced International Studies, said such activity could be carried out as part of preparations for a nuclear test, as was the case in January, or to conceal such preparations.
It said commercial satellite images of the West Portal of the Punggye-ri test site taken Tuesday showed two small ore carts on a track crossing a road from a tunnel entrance.