Satellite imagery from June 9, 2025 showed an unusual convoy at the entrance to an underground nuclear complex near Isfahan. The convoy contained a flatbed truck carrying 18 large, sealed barrels in a configuration which experts said is consistent with the transport of hazardous or sensitive material. Some analysts theorized that the barrels may have contained highly enriched uranium or other materials used in the nuclear fuel cycle, while others raised the possibility of deliberate signaling or deception by Iran. The timing of the delivery days before Israeli airstrikes on Iranian nuclear facilities suggests Iran may have moved key nuclear assets ahead of the strikes.