By Aresu Eqbali in Tehran, Iran, and Isabel Coles in Baghdad 

Iran's top paramilitary force threatened to crack down on Iranians protesting a rise in fuel prices, as Tehran struggles to counter U.S. sanctions that are crippling the country's economy and posing a risk to the government.

As demonstrations persisted on Monday, the powerful Islamic Revolutionary Guard Corps said it would "confront the continuation of any insecurity and actions disturbing the people's peace and calm in a revolutionary and decisive way."

The unrest shows the widespread anger among Iranians whose savings have evaporated as unemployment soars and the currency collapses, posing a political risk for President Hassan Rouhani ahead of February parliamentary elections.

Supreme Leader Ayatollah Ali Khamenei, who oversees the Guard Corps, said on Sunday that the legislative, administrative and judiciary branches of government made the decision, which he supported. The statement showed how the crisis has forced the regime to put on a unified front.

The Guard Corps' warning comes as Iran's government said an unspecified number of police officers were killed during the protests, while public and private infrastructure -- including banks, gas stations and security bases -- were burned and destroyed since protests broke out over the weekend.

Sporadic protests continued on Monday in several cities, including Mahshahr in southwestern Iran, Iran's semiofficial ILNA news agency reported. The scope and scale of the demonstrations have been difficult to determine, since the government has restricted internet access.

Henry Rome, Iran analyst for Eurasia group, said Iran's leadership had taken a calculated risk in raising fuel prices to help the economy and appeared to be prepared for the backlash it would provoke. Security forces were ready to deploy en masse; the internet was ready to be essentially turned off immediately; and a complex plan to distribute cash to 60 million people was on standby.

"I don't think we're seeing the prelude to a revolutionary tipping point, " Mr. Rome said. "Everything the government has done up to this stage indicates they knew protests would follow, but they went forward with the austerity measures anyway."

The protests come at a sensitive time for Iran, which is feeling the heat of popular uprisings against governments it supports.

In neighboring Iraq, protesters rejecting foreign interference in the country's affairs are directing their ire against Iran. In Lebanon, demonstrators are protesting Iran's role in the country, where it supports the political and military group Hezbollah, a pillar of the government.

The protests come as the U.S. pressures Iran with sanctions after President Trump withdrew Washington from the 2015 multilateral Iran nuclear deal. The U.S. wants Iran to scale back what it calls Tehran's interference in the region and its nuclear and military ambitions. The U.S. government voiced support for the Iranian people in their protests over the weekend.

Abbas Mousavi, Iran's Foreign Ministry spokesman, said the U.S. was in no position to express sympathy for the Iranian people because the hardships that had driven them into the street were a result of Washington's "economic terrorism."

Iranians had protested against inflation and high unemployment even before the U.S. reimposed sanctions. Street protests in late 2017 evolved into the most widespread challenge to the government in nearly a decade, with protesters demanding an end to the government and Mr. Khamenei's rule. Since then, hundreds of outbreaks of labor unrest have emerged, piling pressure on Iranian leaders for failing to deliver better living conditions.

Rioters had exploited the latest protests to set fire to banks and gas stations, raid military and police bases, gas and telecommunication infrastructures and private property, government spokesman Ali Rabiei said.

"The government acknowledges the right of people to protest, but a protester is different from a rioter," Mr. Rabiei said.

Nearly 1,000 people have been arrested across the country since Friday night, when the government announced it was raising the fuel prices, while over 100 banks and 57 big stores have been set on fire or plundered in a single province, the Fars news agency reported.

Mr. Rabiei told reporters the internet connection would be restored on Monday or Tuesday, predicting the protests would tail off.

Meanwhile, state television on Monday broadcast footage of pro-regime rallies and the funeral of a major who was killed in clashes with protesters in the western Iranian city of Kermanshah.

Early estimates contained in a report of an intelligence body by the Fars news agency found nearly 87,000 people in protest rallies and gatherings since Friday night.

"The identical methods of the main core of violent rioters discloses that they are fully trained individuals who have been prepared and looking forward for the situation to rise, unlike most people who have been taken off guard by the sudden hike in gas price," the report said.

Write to Isabel Coles at isabel.coles@wsj.com

(END) Dow Jones Newswires

November 18, 2019 15:45 ET (20:45 GMT)

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