A former Iranian intelligence official told a U.S. website that there was a mysterious explosion at Iran's Fordow nuclear facility. 
The website WND, formerly WorldNetDaily, reported Hamidreza Zakeri, a former member of the Islamic Republic's Ministry of Intelligence and Security, said the Monday blast trapped 240 workers in the underground facility. It was unclear whether the workers had been rescued.
The Iranian regime called the explosion sabotage and said explosives disguised as equipment were transferred to the site, WND said. The blast occurred at the third centrifuge chambers with high-grade enriched uranium reserves below. Iran's intelligence agency received information from an alleged spy working in Israel's Mossad that plans were under way to target Iran's nuclear sites, the report alleged.
WND said U.S. officials were informed of the explosion, however, reports of the blast had not been verified or denied by Iran or the West.
The explosion was felt in a 3 mile-radius from the facility and Iranian security forces imposed a no-traffic zone in a 15-mile radius surrounding the facilit y. Tehran-Qom highway was shut down for a number of hours, the website said.
The Fordow nuclear facility is 350 feet under the mountain. Two elevators were said to be out of commission from the explosion and an emergency exit southwest of the site was unreachable, the report said.
A day after the explosion, President Mahmoud Ahmadinejad  convened an urgent meeting with senior intelligence and security officials to discuss the blast, the report said.