Just ahead of U.S. sanctions on Iran set to snap back on Monday targeting primarily the energy, shipbuilding, shipping, and banking sectors, Iran's most prominent conservative cleric has announced that if oil exports are halted, Saudi tankers will be confiscated and Gulf countries attacked.

Powerful Shia cleric Ayatollah Ahmad Alamolhoda is the Friday Prayer leader in Mashhad, considered Iran's spiritual capital and among the holiest places in Shia Islam, and sits on the government's "Assembly of Experts" but has no formal government role or decision-making ability. However, he's a powerful leader and chief spiritual force behind Iran's conservative faction who has long been at odds with President Hassan Rouhani.

Iranian opposition sources report that Alamolhoda told his followers during his Friday prayer sermon:

If we reach a point that our oil is not exported, the Strait of Hormuz will be mined. Saudi oil tankers will be seized and regional countries will be leveled with Iranian missiles.

Prominent hardline cleric Ahmad Alamolhoda

The cleric is further reported to have declared that Iran has the power to "instantly" create conditions for $400 a barrel oil prices if it decides to act in the Persian Gulf.

He said as reported in regional opposition media:

If Iran decides, a single drop of this region's oil will not be exported and in 90 minutes all Persian Gulf countries will be destroyed. The UAE and Saudi Arabia will be destroyed in 60 minutes. After 90 minutes the U.S. will have nothing in this country. And we haven't even started with Israel. Beware of the day we go after Israel, too. That's why they want us to round up our missiles.

Though the hardline cleric's rhetoric is often of this fiery tone and threat-laden in nature, it articulates the position of conservative critics who've long pointed out that President Rouhani's risk of entering a deal with the West (the 2015 JCPOA) has utterly failed.

Meanwhile, with less than 24 hours to go before the next and fiercest round of sanctions come back into force, thousands of demonstrators appeared on the streets of Iran holding anti-American banners and chanting "down with the US". Iranian media reported that similar demonstrations were held in multiple cities across the country.

Weekend protests in Tehran marking the anniversary of the US embassy takeover, via AFP

November 4 marks 39 years since the 1979 US embassy takeover after which the Shia Islamic revolution held 52 American staff and Marines hostage for 444 days. In the streets of Iran people could be seen burning effigies of Trump, and torching American and Israeli flags, and even burning dollars.

White House officials have openly declared that Washington is waging "economic war" against Iran, with Secretary of State Mike Pompeo saying on Friday, "The administration's efforts to change Iranian behavior are far broader, far deeper." Hinting that it's part of a broader package that includes covert regime change efforts, he said further, "There are many other lines of effort," and added, "We're simply focused on this line of effort today because of the significance of November 5th."

It will be interesting to see if economic war quickly escalates into a confrontation in the Persian Gulf, something Iran's IRGC has said could be coming many times before. However, as Tehran tries to cling to a lifeline in the form of European countries willing to find ways to circumvent the U.S.-led sanctions, it is unlikely that the Rouhani government would ever give the order - yet those IRGC operatives loyal to the hardline clerics might.