Iran says it has arrested dozens of alleged spies, including several it accuses of sending nuclear secrets abroad to Iran's enemies.
Iran's official news agency IRNA reports the Intelligence Ministry said most of those arrested were linked to the People's Mujahadeen Organization, an Iraq-based Iranian opposition group.
The ministry said a number of the alleged spies passed nuclear secrets to Iran's enemies abroad.
Since 2002, the opposition group has publicly disclosed what has turned out to be reliable information about Iran's nuclear program. Most notably, the presence of what had been a previously undeclared uranium-enrichment facility located in the center of the Islamic Republic. The group has also accused Iran of attempting to cover up a biological weapons plant in Tehran.
According to an expert on Iran and lecturer at Cairo University, Amal Hamada, Iran may have publicly acknowledged the arrests as a way of trying to accuse Israel of spying on Iran, following Washington's recent disclosure regarding possible espionage at the Pentagon by an Israeli citizen.
"Over the past couple of days we have heard the issue of the American disclosure of an Israeli spy in the Pentagon," she said. "And, that this person in particular has information regarding Iran and its nuclear program. So, maybe the Iranian disclosure is some way of sending a message to the international community that we, too, discovered such a thing."
Iran has maintained its nuclear program is solely for the peaceful production of electricity. But several countries, including the United States, have accused Tehran of building a secret nuclear-weapons program.
Iran has allowed for tough inspections by the International Atomic Energy Agency, which plans to hold new discussions about Iran's nuclear program beginning next month.