Guardian Conflicting reports have emerged from Iran over an explosion heard in the central city of Isfahan, close to the countrys sensitive nuclear facilities. Irans semi-official Isna news agency quoted a judiciary official in Isfahan, saying that an explosion had been heard. We heard a sound similar to that of an explosion but we have received no reports about its causes and the consequences so far, said Gholamreza Ansari, in quotes carried by Isna.