The security forces have been filmed using firearms, water cannon and tear gas to disperse protesters, with security officials also beating demonstrators with batons.
The foreign ministry also criticised the USA for expressing support for the protesters.
Iran's shock decision to increase fuel prices Friday sparked the protests in which authorities have confirmed at least five deaths, including three security personnel officials say were stabbed and fatally wounded by "rioters".
The United States has condemned Iran for using "lethal force". The move is part of efforts to mitigate the effects of crippling USA sanctions on Iran's economy.
According to Iranian ISNA News Agency, the decision to shut down the internet was made by the Supreme National Security Council of Iran.
Days of protests in Iran round climbing gasoline costs and a subsequent federal authorities crackdown have killed at the very least 106 people all through the Islamic Republic, Amnesty Intercontinental talked about Tuesday, citing "credible studies". In a tweet on Saturday, Mr. Pompeo said in response to the demonstrations that "the United States is with you". But the fact that the internet is still down, and that schools in dozens of cities are closed, suggests that the unrest is far from over.
Given that higher gasoline prices would impact the lower economic classes the most, the IRGC statement was careful not to dismiss the protests outright; the six-paragraph statement praised "the people" for their "wisdom" in not falling for the enemy's traps.
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Numerous injured also reported using counterfeit or black-market products containing THC, notably those marketed as "Dank Vapes". Of these samples, the officials found that 82-percent also tested positive for THC and 62-percent tested positive for nicotine.
Rupert Colville, U.N. human rights spokesman, also called on authorities in Iran to restore the internet service cut off since Saturday and uphold the demonstrators' rights to freedom of expression and peaceful assembly. Petrol in the country remains among the cheapest in the world, with the new prices jumping 50% to a minimum of 15,000 rials per litre.
Since the announcement of Friday, the protests have reached up to 100 cities in the country, and the number of protesters is estimated to have exceeded 87,000.
But social media videos posted in defiance of an internet block showed protests continued in several cities on Monday night and a heavy presence of security forces in streets.
Mr Colville said it was extremely hard to verify the overall number of deaths.
Iranian officials have reported the death of 12 protesters and members of Iran's security forces, and said more than 600 people have been arrested since the protests erupted on November 15 after the government announced it was rationing gasoline purchases and cutting subsidies amid biting USA sanctions imposed after President Donald Trump unilaterally withdrew the United States from a 2015 nuclear agreement.
The government had announced 12 deaths related to the protests by Monday morning, according to a tally by BBC Persian, but activists reported that at least 40 people had been killed.
Reacting to the situation, Iran's Supreme Leader, Ayatollah Ali Khamenei, expressed concerns over the scope of the protests, blaming foreign agents and domestic "hooligans" for the turn of events.