At least four people have been arrested in Iran for trying to sabotage a nuclear site, Iranian media reported Sunday.

The head of Iran's Atomic Energy Organisation, Ali Akbar Salehi, said officials had monitored and then arrested a "number of saboteurs" before they could carry out their plan.

"Four of these individuals were caught red-handed and their interrogations are ongoing," he said, according to the Mehr news agency on Sunday.

He did not identify which nuclear site they were planning to damage or when the suspects had been detained.

Israel sees Iran's atomic work as a threat and has said it will attack Iran's nuclear sites if it does not end its program. Iran says its nuclear work is purely peaceful.

Iran periodically announces the arrest of suspects charged with espionage or attempts to sabotage its nuclear facilities. But it normally does not release further details on their identities or fate.

Iranian President Hassan Rohani told the United Nations General Assembly last month that use of nuclear weapons is a "crime against humanity" and called on Israel to join the Nuclear Non-Proliferation Treaty.

In a rare direct reference, Rohani said that "Israel, the only non-party to the Non-Proliferation Treaty in this region, should join thereto without any further delay," according to AFP.

Iran accuses Israel and the West of being behind the assassination of Iranian nuclear scientists and of trying to damage its program in other ways, such as by cyber attack.