CNN reported that images it obtained and analyzed with the Institute for Science and International Security showed renewed activity at the Parchin military complex and near an underground facility known as Mount Pickaxe.

The apparent reconstruction has raised questions about whether Tehran is complying with a memorandum of understanding signed with the United States in late June. Under that agreement, Iran committed to halt efforts related to the acquisition or development of nuclear weapons.

At Parchin, a military complex southeast of Tehran, satellite images taken in June and July reportedly showed work around a structure previously damaged by bunker-buster munitions.

The site has long been suspected of housing activities connected to the development or storage of high explosives that could be used in a nuclear weapons program. Iran has denied pursuing nuclear weapons.

Temporary coverings were initially placed over openings created by the strikes, according to the imagery. Those coverings were later replaced with mesh screens, while concrete-mixing trucks were seen near the site.

Analysts who reviewed the images told CNN the activity suggested Iranian crews may be preparing to seal the openings.

Additional vehicle activity was also observed near tunnel entrances at Mount Pickaxe, an underground complex linked by outside analysts to Iran’s advanced nuclear capabilities.

Experts cited in the report said the activity could represent a violation of the agreement with Washington if Iran is restoring facilities covered by the memorandum.

Other major nuclear sites, including Isfahan, did not show comparable signs of reconstruction in the imagery reviewed by CNN.

Repair work was also visible at several military facilities.

At a missile base in Tabriz, crews appeared to be resurfacing a road, while excavators were seen clearing tunnel entrances at a facility in Kermanshah. At an airbase in Tabriz, workers appeared to be filling a large crater left by earlier attacks.

The imagery became publicly available after the U.S. government eased restrictions that had limited the release of commercial satellite images from the region.

The images show activity at the sites, but do not on their own establish the purpose of the repairs or confirm that Iran has resumed prohibited nuclear work. Tehran has not publicly acknowledged violating the agreement.