A massive blast was reported Monday near the Iranian city of Isfahan, which houses Iran's sensitive nuclear facilities. Residents of Isfahan said they heard the explosion clearly, and the semi-official Iranian news agency Fars initially reported that the incident occurred at 2:40 p.m. local time, but later retracted the report and denied that anything had occurred. A uranium enrichment facility monitored by the International Atomic Energy Agency is located in Isfahan, although most of Iran's centrifuges are located in a nuclear facility in Natanz. If an explosion did occur, it would be the second massive explosion in Iran in the span of two weeks. A huge blast at a missile base west of Tehran killed 17 members of Iran's Revolutionary Guard and wounded 15 others earlier this month. Among those killed was Hasan Moghaddam, a senior commander who was considered the founder of Iran's ballistic missile program. The explosion occurred just days after the U.N.s International Atomic Energy Agency issued a scathing report on Iran's nuclear program, and at a time of mounting tension with Israel and the West. Iranian officials explained that the first explosion as an accident resulting from the relocation of munitions at a base in Bigdeneh, some 45 km (28 miles) west of the capital. Get the Israel Hayom newsletter sent to your mailbox! Initial reports described residents of Isfahan as panicked and calling emergency services after hearing an explosion. The Deputy Governor of Isfahan province, Mohammad-Mehdi Ismaili, initially confirmed the reports, saying that authorities were investigating the incident, according to the Fars news agency. However, when international media agencies began covering the explosion, Fars stopped reporting on the incident, sowing confusion about what exactly happened. "An explosion was heard in the afternoon, but no information was provided by security forces about its origin," Gholamreza Ansari, a judiciary representative in Isfahan, said to the Iranian Students' News Agency. The Mehr news agency quoted other Iranian news agency reports saying an explosion occurred at a gas station in a city near Isfahan. After initially confirming the explosion, Ismaili retracted his statement, and said that Fars had fabricated the quote. "I didn't hear any noise at all in Isfahan," Ismaili said. Later, in an interview with the state-run IRNA news agency, he denied having spoken with Fars reporters altogether. Emergency service representative Masoud Anayeb also denied that an explosion occurred in Isfahan. Isfahan province Governor Alireza Zakeri went a step further in a conversation with the Revolutionary Guard-linked Rajanews, saying that the blast was actually part of a military exercise conducted in the north-east sector of the city. Zakeri denied the incident had anything to do with the nuclear facilities in the area. "Nothing of the sort happened. The noise was from a military drill," Zakeri said. Despite the Iranian denials, Saudi-owned network Al Arabiya quoted an Iranian official as saying that an explosion did occur in an armaments warehouse in the city. U.S. defense and IAEA officials said they were not aware of an explosion in Isfahan. U.S. State Department Spokesman Mark Toner said, "We dont have any information at this time, other than what weve seen in the press as well, but certainly were looking into it. As you know, were somewhat limited in our ability to glean information on the ground there, but were certainly looking into it." Israeli military intelligence chief Brig. Gen. Itai Baron addressed the Knesset Foreign Affairs and Defense Committee on the Nov. 12 blast, saying that "the explosion occurred in a surface-to-surface missile development base, and may delay or terminate the development of that line of missiles. But Iran has other lines of development, and its nuclear program is moving ahead despite the pressures directed against it." Intelligence Minister Dan Meridor remarked on the events Tuesday, saying that "not every explosion in Iran should be automatically viewed as a scene from an espionage movie." Speaking to Army Radio, Meridor said, "In recent years, many countries have made efforts to prevent Iran from realizing its nuclear aspirations. Iran is currently facing difficulties on several fronts. Some countries impose economic sanctions and some use other methods." Like our newsletter? 'Like' our Facebook page!