Iran Car Bomb
The bombed-out car of Iranian nuclear scientists Mostafa Ahmadi-Roshan, who was killed in Tehran in January. Iran says it has discovered who was behind the assassination. Reuters

Iran's Intelligence Ministry said on Tuesday that it has uncovered a large and sophisticated Israeli-backed terrorist network that was planning attacks inside Iran.

According to the official Fars news agency, after months of investigation Iran arrested terrorists who had been plotting an attack in the near future, while discovering a large cache of explosives, guns, ammunition and military and telecommunication tools.

[We] have discovered one of the biggest terror and sabotage networks of the Quds [Jerusalem] Occupying Regime [Israel] and protected cells of its operatives and arrested groups of criminal terrorists and mercenaries cooperating with them, the Intelligence Ministry said in a statement.

The complicated and months-long measures and moves made by the Iranian intelligence forces to identify the devils led to the discovery of the Zionists' regional command center in one of the regional countries and discovering the identity of the agents active in that command center.

The ministry didn't name the terrorist organization nor detail its connection with Israel, but said more information would be forthcoming. Iran's Press TV insinuated that the terrorists could be Israeli spies working for the Mossad, or even CIA agents. Last November, Tehran claimed to have arrested 12 Iranians recruited by the CIA to be informants and to sabotage the country's nuclear program.

We have 100 unbeatable documents on the U.S. role in directing terror and terrorists in Iran and the region, supreme leader Ayatollah Ali Khamenei said at the time. By releasing these documents, we will dishonor the U.S. and those who claim to be the advocates of human rights and campaign against terrorism among the world public opinion.

Israel has also been linked to a string of assassinations of Iranian nuclear scientists, the most recent being Mostafa Ahmadi Roshan, a university chemistry professor who doubled as a director of Iran's Natanz uranium-enrichment facility. He was killed in Tehran in January after two assailants on a motorcycle attached a magnetic bomb to his Peugeot car.

Roshan's killing was nearly identical to a November 2010 attack in Tehran in which nuclear engineer Majid Shahriari died and Fereydoon Abbasi Davani, head of Iran's Atomic Energy Organization, was wounded.

In addition, intelligence specialists have linked Mossad to an explosion at a Revolutionary Guard base about 30 miles west of Tehran last November; the blast killed 17 people including Maj. Gen. Hassan Tehrani Moqaddam, Iran's most senior missile commander.

Iran believes that Israel would not act without first getting approval from the United States. The State Department has firmly denied having advanced knowledge of the attacks, but Israel has neither confirmed or denied its involvement in the car bombings.

In March, a controversial report suggested that Israel was using Azerbaijan as a secret military staging ground to carry out attacks against Iran in the near future, and the Azeri capital Baku is now allegedly a hotbed of spy activity. Both Israel and Azerbaijan have called the report absurd and groundless.

While the Iranian Intelligence Ministry has yet to name names, Tuesday's arrests have again drawn speculation to the People's Mujahedin of Iran -- an Iraq-based Iranian dissident organization known variously as the PMOI, Mujahedin-e-Khalq and MEK.

The MEK is officially listed as a foreign terrorist organization in the United States, and has been linked to militant activities in the past. MEK says it has abandoned its violent past -- it is now recognized as a peaceful opposition group in Europe -- and has recently garnered the support of numerous former top-rank American officials.

Nonetheless, two senior Pentagon employees told NBC News last month that Israel's Mossad had been funding and training MEK members to carry out attacks in Iran -- including the assassinations of Roshan, Shahriari and Davani -- and last week the New Yorker revealed that the U.S. Joint Special Operations Command had brought MEK operatives to Nevada for counterintelligence training.

The operatives of MEK and PJAK [Party of Free Life of Kurdistan] are seen as invaluable agents for [Israeli and U.S. spy agencies] Mossad and CIA because they can work covertly inside Iran and carry out various tactical missions rather discreetly. There is little doubt that MEK is actively involved in sabotaging, either directly or indirectly, the Iranian nuclear program, Dilshod Achilov, assistant professor of Middle East politics at East Tennessee State University, told IBTimes last month.

The MEK has denied connections with Israel outright.