US Alert Warns Iranian Sleeper Cells Activating
A federal alert warns Iran may be activating sleeper cells abroad after U.S.-Israel strikes killed Supreme Leader Khamenei, as Trump vows surveillance of all operatives.
President Trump says the United States is watching every Iranian sleeper cell, but federal intelligence cannot decipher the mysterious transmission sent to agents abroad just hours after Tehran's supreme leader was killed.
Trump made the declaration at a White House press conference March 9, projecting confidence, while a federal alert distributed to law enforcement agencies warned of a possible operational trigger for sleeper cells. Officials said they were monitoring potential sleeper assets but could not determine the content of an encrypted message believed to be an operational trigger for Iranian operatives.
The exact contents of these transmissions cannot currently be determined, according to the federal alert reviewed by ABC News.
The transmission, likely of Iranian origin, was relayed across multiple countries via shortwave radio within 12 hours of the U.S.-Israel joint military strikes that killed Supreme Leader Ayatollah Ali Khamenei on February 28. The numbers station broadcast began with "Tavajjoh! Tavajjoh!" — "Attention! Attention!" — followed by strings of Persian digits twice daily.
Amateur radio enthusiasts designated the signal V32 and detected it across Europe and the Middle East. Experts remain divided on whether the transmission originates from Iran sending messages to agents abroad or from an adversary sending to agents inside Iran.
What officials can confirm is that Iranian sleeper cells may be activating outside Tehran's borders following the strikes. Qatar announced March 2 that security forces arrested 10 suspects affiliated with the Iranian Revolutionary Guard. Seven were assigned to spy on military facilities, three were tasked with sabotage. The suspects had coordinates of sensitive facilities and communication devices.
Azerbaijan's State Security Service announced March 5 it dismantled an Iranian spy cell planning terror attacks on the Baku-Tbilisi-Ceyhan pipeline, the Israeli Embassy and a synagogue. Authorities detained multiple suspects and seized 7.7 kilograms of C-4 explosives and remote-controlled bombs.
In the United States, investigators are working to establish whether the March 1 Austin shooting fits a pattern. The suspect, Ndiaga Diagne, wore clothing displaying an Iranian flag emblem and had replied on social media to Iranian Foreign Minister Abbas Araghchi's statement that strikes on Iran would be immediately reciprocated.
The FBI stated Diagne was not previously on their radar. Officials said assigning a motive would be premature.
The concern about Iranian sleeper cells builds on decades of documented plots against American targets. A federal jury convicted an Iranian operative Asif Raza Merchant March 6 of terrorism charges for a plot to assassinate Trump in 2024. Merchant was recruited by the Revolutionary Guard.
Iran has a history of assassination attempts on U.S. soil dating back at least 46 years, including a 2011 attempt to bomb the Saudi ambassador in Washington using a car salesman as a proxy.
Customs and Border Protection Commissioner Rodney Scott warned in a memo dated March 9 that thousands of Iranian nationals have been documented entering the United States illegally. The threat of sleeper cells or sympathizers acting on their own, or at the behest of Iran has never been higher, Scott wrote.
Security experts say Iran's reliance on asymmetric warfare explains the current pattern. "A country like Iran does not have the capability to beat us militarily, so they rely on asymmetric means," Elizabeth Naumann, former DHS Assistant Secretary for Counterterrorism, told ABC News.
"If ever there's going to have a Hezbollah cell or a Hamas cell act in the U.S. in a violent way, it's now, because their back is against the wall," Chris Swecker, former Assistant FBI Director, told Fox News.
"The fact is nobody, if they're speaking honestly, from U.S. intelligence or law enforcement can tell you as a matter of fact how badly we've been infiltrated here in the United States," Charles Marino, former DHS senior adviser, told the Daily Mail.
The FBI stated it had no comment when asked about Trump's remarks on sleeper cells. The Department of Homeland Security did not respond to requests for comment.