The exact purpose of the site which was attacked is uncertain
The Iranian defence ministry says it has foiled a drone attack on a military facility in the city of Isfahan.
The ministry said the site suffered only minor damage, though this has not been independently verified.
The Wall Street Journal and New York Times quoted unnamed US officials as saying Israel was behind the attack.
Israel has not commented. The purpose of the site is unclear, though reports suggest it could be connected to missile production.
Iran’s defence ministry said three drones were involved in the attack on Saturday night at about 23:30 (20:00 GMT). It said one was destroyed by air defence systems and two were caught by “defence traps”, causing minor damage to a building. There were no casualties, it said.
Local authorities did not comment on activities at the site, but called it a “workshop”. Iran’s official Irna news agency said the drones had targeted “an ammunition manufacturing plant”.
Isfahan province is home to a large air base, a major missile production complex and several nuclear sites.
Pentagon spokesperson Brig Gen Patrick Ryder said the US military played no part in the strikes, but declined to speculate further, Reuters news agency reported.
The Wall Street Journal quoted unnamed “US officials and people familiar with the operation” as saying Israel had carried out the attack. The New York Times said it was the work of the Mossad, Israel’s intelligence service, according to “senior [US] intelligence officials”.
If confirmed it would mark the first such known attack on a facility in Iran under the current Israeli government which came to power under Benjamin Netanyahu at the end of December.
Israel has previously admitted to carrying out hundreds of strikes against Iranian targets in Syria, which it says is aimed to stop the transfer of weapons from Iran to militants in Lebanon.
Iran does not recognise Israel’s right to exist and the two countries are bitter foes.
Iran’s Foreign Minister Hossein Amir-Abdollahian said the “cowardly” incident on Saturday night was an attempt to destabilise the country.
The attack comes amid heightened tensions over Iran’s nuclear programme and its supply of arms to Russia’s war in Ukraine.
The country has also been wracked by internal turmoil in recent months, spurred by the death of a woman who was detained for violating Iran’s strict dress code.
In a separate incident on Saturday, Irna reported a fire broke out at an oil facility near the north-western city of Tabriz. No details about the cause have been revealed.
In recent years, there have been a number of explosions, fires and cyber attacks on Iranian military, nuclear and industrial facilities.
Additional reporting by Josh Cheetham
