Iran's key retaliatory leverage is the disruption of the Strait of Hormuz, which could affect 20 percent of global oil and gas trade, though this would be a last resort, as it could disproportionately affect Iran's own oil trade, S-RM said in an analysis provided to Newsweek .

Huge protests in Iran have galvanised exiled foes of the authorities but despite their hatred of the ruling clerics, a bitter schism dating to before the 1979 Islamic Revolution still afflicts the leading opposition factions.

The videos that have trickled out of the Islamic Republic offer a rare glimpse into the scope of the crackdown.

Iran has imposed a near-total blackout on the internet and other communications, making it difficult to obtain a firm estimate of protester deaths.

Some personnel at the United States’ largest military base in the Middle East have been urged to leave, a US official told CNN on Wednesday, as regional nations press the Trump administration to reconsider taking military action against Iran.

Iran eased some restrictions on its people for the first time in days as the death toll from days of bloody protests against the state rose to at least 2,571 people, according to activists.

The president has told his advisers he would want any action to deliver a decisive blow to the Iranian regime, but so far he hasn't gotten that guarantee from them, sources say.

Turkey's intelligence agency, MIT, warned Iran's Revolutionary Guard about Kurdish fighters trying to cross the Iran-Iraq border during ongoing government crackdowns.