The report by IRNA said an electrical short circuit in an underground site led to the explosion a day earlier.
The incident happened near the port city of Bandar Abbas, some 1,200 kilometers (745 miles) south of the capital, Tehran.
The report did not elaborate, but the disregarding of safety measures is a frequent cause of such incidents in Iran.
An electrical problem was also blamed for a massive blaze in January that killed 26 people and destroyed an iconic building in downtown Tehran.
The Plasco tower was built in the early 1960s by Habib Elghanian,a prominent Iranian Jewish businessman, philanthropist and de facto leader of the Iranian Jewish community in the 1970s under the shah. He was the first Jew and businessman to be executed by the Islamic regime on charges that included contacts with Israel and Zionism and “friendship with the enemies of God.”
Source: / timesofisrael /