Image: The Sunday Guardian

US Intercepts Iran's Encrypted Signal That May Activate Sleeper Cells After Khamenei's Death

10 March, 2026.Iran.9 sources

Key Takeaways

U.S. intercepted encrypted communications believed to originate in Iran
Intercepted transmission may be an operational trigger to activate sleeper assets overseas
Coded message was relayed shortly after Ali Khamenei's reported death on February 28

Intercepted coded radio broadcast

U.S. intelligence agencies reported intercepting an encrypted, coded radio broadcast shortly after the reported death of Iran's Supreme Leader Ayatollah Ali Khamenei on Feb. 28.

“Iran may be activating sleeper cells outside the country, alert says The encrypted transmission was intercepted by the U”

ABC News

Officials say the transmission may have been intended as an "operational trigger" to activate Iranian sleeper agents abroad.

ABC News

Multiple outlets describe the transmission as repeatedly rebroadcast internationally and designed for clandestine recipients holding a decryption key.

Analysts have not yet determined the message's exact contents.

Federal alert on radio activity

U.S. authorities issued a federal alert urging law-enforcement to heighten monitoring of unusual radio-frequency activity while stressing no specific location or imminent attack has been identified.

Agencies including the FBI were ordered to raise counterterrorism vigilance, and major U.S. cities reportedly increased patrols around vulnerable sites as intelligence and law-enforcement partners boosted situational awareness.

Hindustan Times

Escalation amid regional strikes

Analysts and reporting placed the intercepted transmission squarely in the broader escalation between Iran, the U.S. and Israel.

“After Khamenei's death, Iran sent signal to activate sleeper cells: Report While no immediate threat to specific locations has been identified, law enforcement agencies are advised to monitor suspicious activity”

India Today

Outlets linked the signal to the reported Feb. 28 death of Khamenei amid what they described as U.S.-Israeli strikes, reciprocal Iranian actions, and attacks affecting regional targets, and officials warned the episode comes amid elevated risks of reprisals.

Intercepted signal uncertainty

Officials emphasized uncertainty about the intercepted signal’s content and origin.

Preliminary signals analysis judged the transmission likely of Iranian origin.

Mathrubhumi English

Strong encryption left analysts unable to decode the message.

Authorities cautioned there was no confirmed attack plan tied to a specific location.

Security threat and responses

Senior security officials publicly raised the threat level and warned of elevated revenge-attack risks.

“0 arrow-down comments printer search bell top-nav right-arrow left-arrow arrow-down Advertisement After Khamenei's Death, Iran Sent A Signal To Activate Sleeper Cells: Report The war has now entered its ninth day, and the leadership transition following the death of Ali Khamenei has not slowed the fighting”