Significant activity has been spotted at North Korea's main atomic test site's west portal — an as-of-yet unused tunnel complex where little or no activity had been observed over the past several months — raising the possibility of preparations for a fresh nuclear test, an analysis of new satellite imagery showed Monday.
In the report on the Punggye-ri atomic test site, the North Korea-watching website 38 North said that the imagery, dating from Sept. 8 to Nov. 1, showed "significant movement of equipment, mining carts, material and netting within the area" of the west portal after Pyongyang's sixth and most powerful nuclear blast on Sept. 3.
That test — which North Korea has claimed was of a hydrogen bomb — was held at the site's north portal, where the isolated country's last five nuclear tests were conducted.