Iranian defence ministry says a loud blast heard in Isfahan was caused by ‘unsuccessful’ drone attacks.

The attacks were “unsuccessful” and there were no casualties, the ministry said in a statement early on Sunday.

“One of [the drones] was hit by the … air defence and the other two were caught in defence traps and blew up,” said the statement carried by the state news agency, IRNA. “Fortunately, this unsuccessful attack did not cause any loss of life and caused minor damage to the workshop’s roof,” it said.

The ministry did not say who was suspected of carrying out the attack.

The statement came shortly after Iranian media reported a loud blast in Isfahan.

News agencies published a video showing a flash of light at the plant, said to be an ammunitions factory, and footage of emergency vehicles and fire trucks outside the plant.

The ministry said the attack “has not affected our installations and mission … and such blind measures will not have an impact on the continuation of the country’s progress”.

Reports of the drone attacks in Isfahan also came as Iran’s state TV also said a fire had broken out at an oil refinery in an industrial zone near the northwestern city of Tabriz.

It said the cause was not yet known as it showed footage of firefighters trying to extinguish the blaze.

There have been several explosions and fires around Iranian military, nuclear and industrial facilities in the past few years.

They come amid a long-running shadow war between Iran and Israel.

The two countries are at loggerheads over Tehran’s nuclear programme.

Israel says Iran is seeking to develop nuclear weapons, an allegation Tehran denies.

In July last year, Iran said it had arrested a sabotage team made up of Kurdish fighters working for Israel who planned to blow up a “sensitive” defence industry centre in Isfahan.

Iran also blamed Israel for the assassination of its top nuclear scientist, Mohsen Fakhrizadeh, in 2020, as well as an attack on its underground Natanz nuclear facility in April 2021 that damaged its centrifuges.

Israel has not claimed responsibility for the attacks.

Israeli officials rarely acknowledge operations carried out by the country’s secret military units or its Mossad intelligence agency.