American intelligence agencies have intercepted encrypted communications assessed to be of Iranian origin that may be intended to activate sleeper operatives outside Iran, according to a federal alert reviewed by ABC News. The signals were detected soon after the killing of Iran’s supreme leader, Ali Khamenei, in a joint US–Israeli operation on February 28. Analysts noted an unusual pattern in which the encrypted transmissions were rebroadcast across multiple countries, prompting closer scrutiny and heightened monitoring.
Officials said the messages were designed for recipients possessing specific decryption keys, a technique that enables instructions to be transmitted without relying on conventional internet or cellular networks. The alert indicated the communications could be intended to activate or guide pre-positioned sleeper assets operating beyond Iran’s borders. Although the precise content of the signals remains unknown, authorities said the sudden emergence of a new international rebroadcast node justifies increased vigilance. Law enforcement agencies have been advised to watch for suspicious radio-frequency activity, while emphasising that no immediate threat to any specific location has been identified.
The intelligence warning comes amid escalating hostilities across the region. Israel carried out additional strikes on central Iran and on Hezbollah-linked infrastructure in Beirut, following earlier attacks on oil depots in Tehran. Iran responded with missile and drone operations targeting Israel and countries hosting US forces. In Saudi Arabia, two foreign nationals, including an Indian citizen, were killed after a projectile struck a residential area. Iran’s ambassador to the United Nations said at least 1,332 civilians have died and thousands more have been injured in the conflict. The United States also confirmed the death of a seventh American soldier from conflict-related injuries.
US President Donald Trump said Washington is closely tracking whether Iran has activated sleeper cells abroad and that American authorities remain fully engaged in monitoring developments. He stated that US military operations are progressing faster than initially projected and could already be considered largely successful, while indicating that further action would continue. Trump also said US forces have begun targeting Iran’s drone-manufacturing infrastructure, contributing to a sharp reduction in drone launches. Asked about reports of a strike on a girls’ school in Iran, he said the matter remains under investigation.
