Shafaq News / Iranian news agencies on Saturday reported a large explosion in the sky above the town of Natanz, which houses nuclear sites, but that there was no official explanation of the incident.
"Local sources have reported hearing a large explosion in the Natanz sky. No official source has yet confirmed or denied the report," the websites, including Fararunews, quoted the Daneshju (Student) News Agency as reporting.
The semi-official Fars news agency quoted its reporter in nearby Badroud as saying a short-lasting blast was heard which was accompanied by an intense light in the sky.
"No exact details are available about this," Fars quoted the local governor of Badrud as saying.