"On Wednesday morning, a sabotage operation against one of the (Atomic Energy Organization of Iran) buildings was foiled," the broadcaster said, adding that the attack "did not cause any damage in financial or human terms."

It gave no further details on the building or the nature of the sabotage that had been averted.

The incident comes as Tehran and world powers attempt to revive a hobbled 2015 agreement on Iran's nuclear programme in Vienna talks, which an EU negotiator said Sunday were moving "closer to a deal".

That agreement is staunchly opposed by arch-foe Israel, which Iran accused of being behind a "small explosion" that hit its Natanz uranium enrichment plant in April.

Israel neither confirmed nor denied involvement, but public radio said it was a sabotage operation by the Mossad spy agency, citing unnamed intelligence sources.

At the time, Iran's foreign ministry indirectly accused Israel of attempting to scuttle the Vienna nuclear talks.

Wednesday's sabotage attack also comes two days after Iran said it temporarily shut down its only nuclear power plant at Bushehr on the country's Gulf coast.

Officials gave conflicting accounts on an apparent regular maintenance operation at the Bushehr plant on Monday.

The Bushehr plant and its 1,000-megawatt reactor, on Iran's southern coast, were built by Russia and officially handed over in September 2013, despite concerns over its location in an earthquake-prone area.

The 2015 nuclear deal promised Iran sanctions relief in return for limits on its nuclear programme.

The deal was torpedoed in 2018 when then US president Donald Trump unilaterally withdrew from it and reimposed punishing sanctions on Iran.

Trump's successor Joe Biden favours rejoining the accord and the remaining parties are engaged in negotiations in Vienna to try to salvage it.