At least four individuals have been apprehended by Iranian security forces, caught red-handed in an attempt to sabotage a nuclear facility, Iranian media reported on Sunday.

The timing of the arrests and the location the suspects were attempting to sabotage were not given.

“Some time ago, we uncovered sabotage activities by several people at a nuclear plant,” Ali Akbar Salehi, the chief of Iran’s Atomic Energy Organization, said. ”We let them continue their activities so that we could gather more intelligence.”

“We arrested them at the appropriate moment and their interrogation is ongoing,” Salehi said, according to AFP’s translation.

The arrests come during a tentative rapprochement between the Islamic Republic and the United States, spearheaded by Iranian President Hassan Rouhani, over Iran’s nuclear program, which the West and Israel believe is an attempt to develop nuclear weaponry, and over Western sanctions on Iran, which have had a devastating effect on the country’s economy.

Iran’s nuclear program has been targeted several times in the past, including by Stuxnet, a computer virus that was allegedly created by the US and Israel specifically to sabotage it.

In January 2012, an Iranian nuclear scientist and a director of the Natanz uranium enrichment facility in central Iran was assassinated when a bomb was affixed to his car by two assailants on a motorbike in Tehran. The victim’s family later filed a lawsuit again Israel, the US and Britain, accusing them of being behind the assassination. The Iranian government has accused Israel of several other assassinations, including that of four other nuclear scientists and the head of the country’s ballistic missiles program.

Last week, a key Iranian cyber war operative may have been killed in an “internal dispute,” cabinet minister and former Shin Bet intelligence chief Yaakov Peri said Thursday. The official, Mojtaba Ahmadi, was shot north of Tehran by two men riding a motorcycle.

Times of Israel staff contributed to this report.