The US may have intercepted an encrypted transmission intended for Iranian sleeper cells or covert operatives, ABC News reported on Monday.
According to a law enforcement alert which ABC News reportedly reviewed, the transmission was relayed internationally shortly after former Iranian supreme leader Ayatollah Ali Khamenei was killed by an Israeli airstrike.
The transmission, which was encoded, could "be intended to activate or provide instructions to prepositioned sleeper assets operating outside the originating country," ABC News reported the alert as saying.
The alert stated that there was no specifically known threat for law enforcement agencies, but that "the sudden appearance of a new station with international rebroadcast characteristics warrants heightened situational awareness."
Experts warn of potential Iranian sleeper cells
Experts have warned of the potential activation of Iranian sleeper cells across the West amid the ongoing US-Israel military action.
Concerns were particularly raised after two Iran-related violent incidents took place last week - one in Austin, Texas, and one in Toronto.
Iran threatened US President Donald Trump last year that it would activate US-based sleeper cells should he order strikes on Iran’s nuclear facilities, not long after the US struck three facilities.
Mathilda Heller contributed to this report.