An explosion in a supermarket in the southern city of Shiraz injured 37 people and may have been caused by a gas leak, Reuters quoted Iranian state media as saying on Saturday.
The blast occurred at 12.45 a.m. (2115 GMT) in the city's Hypermarket center, the reports said.
The head of fire department in Shiraz, Mohammad Farokhzadeh, told state television that a gas leak or an explosion of flammable items stored in the supermarket could be the cause. He said an investigation was underway.
The explosion was loud enough to be heard in most neighborhoods of Shiraz. The walls of the supermarket had collapsed.
Videos published on social media showed fire had reached the second storey of the building which is partly residential. Windows were shattered in shops and buildings on the street.