A mysterious blast which reportedly rocked Isfahan in western Iran on Monday damaged a key nuclear facility in the city. Isfahan is known for its uranium conversion plant which has been operational since 2004. At first, Iranian officials denied the reports, with the governor of Isfahan later alleging that the blast was caused by an accident that had occurred during a nearby military drill. The Isfahan plant took uranium from mines and produced uranium fluoride gas, which then fed the centrifuges that enrich the uranium.