Iran Sends Suspected 'Operational Trigger' To Activate Sleeper Cells Abroad, U.S. Intelligence Warns

U.S. intelligence agencies intercepted an encrypted radio-style transmission shortly after Iran’s Supreme Leader Ali Khamenei died on Feb. 28.

“Iran activated sleeper cells across the globe after Khamenei's death: Report The coded signal was reportedly transmitted after the death of Iranian Supreme Leader Ali Khamenei on February 28”

Hindustan Times

U.S. officials and multiple outlets say the transmission may have been intended as an 'operational trigger' to activate Iranian sleeper assets abroad.

Hindustan Times

Reports describe the message as encoded for clandestine recipients and repeatedly rebroadcast by a newly observed station.

Authorities have not been able to decode the transmission and say its exact contents remain unknown.

A federal alert reviewed by ABC News raised concern because the signal appeared to contain instructions for 'covert operatives or sleeper assets'.

A federal memo and law-enforcement alert described the transmission as using a radio-style broadcast system that can deliver encrypted instructions to recipients who possess the proper keys.

They urged agencies to monitor unusual radio-frequency signals.

International Business Times UK

Analysts say the message was repeatedly rebroadcast internationally and appeared encrypted for "secret users".

Officials have not tied the broadcast to any specific threatened location.

The advisory called for heightened situational awareness and increased surveillance of suspicious radio-frequency activity rather than declaring a location-specific plot.

U.S. counterterrorism and law-enforcement agencies stepped up surveillance and security preparations nationwide.

“A federal government alert had been sent to law enforcement agencies, ABC News said”

London Evening Standard

The alert advised heightened vigilance and officials warned law enforcement to increase monitoring for suspicious radio signals.

The Hindustan Times and The Sunday Guardian report that FBI director Kash Patel ordered counterterrorism and intelligence teams to be on high alert, and former officials publicly urged vigilance given the potential for Iran-aligned groups to act in retaliation.

Analysts and outlets placed the intercepted transmission in the wider context of escalating strikes and reprisals.

The National Bulletin and Hindustan Times linked the alert to ongoing U.S. and Israeli airstrikes on Iranian-linked forces, reciprocal Iranian attacks on Israel and Gulf states, and Israeli strikes on Hezbollah in Lebanon.

Mint

The Telegraph framed the interception as part of broader Western concerns about Iran activating cells in Western countries and connected the story to domestic security threads including MI5 and cyber activity, underscoring why Western intelligence services were alert to potential cross-border threats.

Multiple outlets stress that analysts have not been able to decode the transmission.

“Iran sent out a possible “operational trigger” to activate “sleeper assets” abroad after the war with America and Israel began, according to an encrypted message intercepted by the US”

New York Post

A federal memo did not identify a specific attack plan or location.

New York Post

Reporting shows divergent language about Khamenei's status: some pieces refer to his death or reported death on Feb. 28, while at least one report asserts he was killed in a joint U.S.-Israeli strike.

The public record contains inconsistent characterizations that the alerts and memos do not resolve.

Overall, the coverage characterises the intercepted signal as potentially designed to reach prepositioned operatives but leaves open whether any operational orders were actually delivered or acted upon.