The Institute for Science and International Security said it has obtained DigitalGlobe satellite imagery from May 25 showing visible tracks made by heavy machinery used in the demolition process
ISIS said the two buildings were intact in an April 9 image.
"These activities raise further concerns of Iranian efforts to destroy evidence of alleged past nuclear weaponization activities," ISIS said.
Iran has refused repeated requests by inspectors to visit the site and the security think tank said the newest images raise concerns that Iran is attempting to raze the site prior to allowing a visit by inspectors.
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