The Institute for Science and International Security said newly available satellite imagery appeared to show possible new defensive measures at Iran’s underground Pickaxe Mountain (Mount Kolang Gaz La) complex near the Natanz nuclear site.
The Washington-based institute said imagery suggested that by late April, two eastern tunnel entrances at the site had been partially blocked with grey earthen material that could hinder rapid vehicle access and would likely require heavy equipment to clear.
The institute said the entrances had appeared unobstructed in imagery from earlier in the month.
It added that the material did not fully conceal the tunnel portals, unlike measures previously observed at tunnel entrances at Fordow and Esfahan.
The institute said the activity raised “significant questions” because the deeply buried complex could potentially be used to store sensitive equipment or materials.
It also noted that older tunnel portals linked to a separate complex dating back to 2007 at Pickaxe Mountain had earlier this year been buried and reinforced with concrete, which analysts said could suggest equipment or material had been moved into the tunnels.
