WASHINGTON

The US has intercepted encrypted communications believed to have originated in Iran that may serve as an operational trigger for sleeper cells outside the country, according to a report published on Monday.

ABC News said it reviewed a federal government alert sent to law enforcement agencies citing “preliminary signals analysis” of a transmission likely of Iranian origin, relayed across multiple countries shortly after the death of Iran’s Supreme Leader Ali Khamenei in a reported US-Israeli attack on Feb. 28.

The alert reportedly said the encoded message appeared intended for clandestine recipients possessing the encryption key and may be meant to activate or provide instructions to covert operatives abroad, though authorities said no specific operational threat has been identified.

The report comes amid a series of US and Israeli strikes on Iran that began on Feb. 28, killing more than 1,200 people including Supreme Leader Ayatollah Ali Khamenei, over 150 schoolgirls and senior military officials.

Iran retaliated with barrages targeting US bases, diplomatic facilities, and military personnel in the region. Seven US service members have been killed amid the ongoing conflict.