The United States said they knew that Iran would attack major cities without warning.
Iran has promised that America is waiting for “brutal revenge” after an air strike in Iraq that killed a senior Iranian general.
The US fears that sleeper cells may be ready to attack in major cities.
The killing of Maj. Gen. Qassem Soleimani, the head of Iran’s elite Quds Force, on Friday marks a major escalation in the standoff between the U.S. and Iran.
There are fears that the Iran-backed Hezbollah militant group, which has been designated by the U.S. government as a foreign terrorist organization, may have sleeper cells in the U.S. that are ready to retaliate.
Former CIA operations officer, Sam Faddis, warned that Hezbollah sleeper cells were hiding in the U.S. and potentially had targets in its sights.
“It is more than possible that Hezbollah has sleeper cells in the United States ready to strike,’ Faddis told DailyMail.com.
“Based on what we know, we must accept that they do and that they can reach US soil at any time without warning.”
Iran’s Supreme Leader Ayatollah Ali Khamenei has warned that “heavy revenge” awaits America after an air strike.