Iranian state media said on Wednesday that the country had foiled a sabotage attempt against a building of the Iranian Atomic Energy Organization, adding that it caused no "loss of life or property damage."
There was no confirmation of the report from the Iranian authorities.
"Investigations are ongoing to identify the perpetrators and determine the facts surrounding the incident," said Nournews, an Iranian news agency close to Iran's Supreme National Security Council.
Iran's English-Language Press TV reported that "the hostile attempt occurred on early Wednesday, but did not result in any casualties or damage owing to tight security precautions adopted following similar acts of sabotage against Iranian nuclear sites and scientists."
Iran has accused Israel of several attacks on facilities linked to its nuclear program and killing its nuclear scientists over the past years.
Israel has neither confirmed nor denied the allegations, but the former head of the Mossad intelligence agency Yossi Cohen earlier this month offered the closest acknowledgment yet that Israel was behind recent attacks of this nature.
Earlier this week Iranian officials said the country's sole nuclear power plant has been temporarily shut down due to a "technical fault."
Iranian state TV reported on Sunday the Bushehr nuclear power plant had undergone a temporary emergency shutdown, but did not provide an explanation.
The country's atomic energy body made the announcement confirming the reasons for the shutdown on the night between Sunday and Monday.
"Following a technical fault at Bushehr power plant, and after a one-day notice to the energy ministry, the plant was temporarily shut down and taken off the power grid," the Atomic Energy Organization of Iran said on its website around Sunday midnight.
The statement said the plant will be reconnected to the grid and the issue will be resolved "in a few days", but did not elaborate further. Repairs were projected by the plant's operating company to continue until at least Friday.