AlHijjah 16, 1432, Nov 12, 2011, SPA -- At least 15 members of Iran's Revolutionary Guards were killed Saturday in an explosion at a military base west of Tehran, the ISNA news agency reported. The blast took place at the base in Malard and Shahriar, a spokesman for the governor's office said. ISNA quoted unnamed officials as saying that the explosion was in the base's ammunition depot. It remains unclear what caused the blast, dpa reported.