On Sunday, Iran's Supreme Leader Ali Khamenei blamed violence during the rallies on criminal and foreign influence, while backing the government's decision.
"Some people are no doubt anxious by this decision. but sabotage and arson is done by hooligans not our people", the Iranian Supreme Leader said in a live speech on state TV.
Riot police clashed with protesters on Saturday, leaving at least one dead in the southeastern city of Sirjan, according to Iranian media.
Khamenei said the increase in gasoline prices was based on expert opinion and should be implemented, but he called on officials to prevent hikes in prices of other goods.
His comments come as the government shut off internet across Iran in an attempt to quell protests over the raising of government-set gasoline prices by 50%.
Iran's Intelligence Ministry said in a statement reported by Tasnim news agency that the protest's leaders had been identified and "appropriate action" was being taken. He said on Sunday that Iran's enemies were responsible for the sabotage and arson.
In Kermanshah, a policeman died Sunday, a day after a "confrontation with a number of rioters and thugs", the provincial police chief told IRNA.
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Following his speech, parliament cancelled a motion to reverse the price hike, semi-official news agency ISNA reported.
The protests put renewed pressure on Iran's government as it struggles to overcome the US sanctions strangling the country after President Donald Trump unilaterally withdrew the United States from Tehran's nuclear deal with world powers.
Access to the internet has been restricted since the demonstrations broke out. "Tehran has fanatically pursued nuclear weapons and missile programs, and supported terrorism, turning a proud nation into another cautionary tale of what happens when a ruling class abandons its people".
Videos on social media showed riot police firing teargas and using clubs on Saturday to disperse protesters in several cities. Public outrage was provoked by the government's decision to raise gasoline price from 10,000 rials per liter to 15,000, which translates into about $0.13 a liter, or about $0.50 a gallon. Also, compared with 2009, fewer worldwide media outlets have correspondent in Iran to report on events.
Iranian journalist Masih Alinejad tweeted a video of protesters setting fire to a statue of Ayatollah Ruhollah Khomeini, the founder of the Islamic Republic, in Shahriyar, a city in Tehran province. The footage could not be verified by Reuters, along with other images on social media.
Iran often accuses exiled opponents as well as the United States, Tehran's arch-enemy Israel and its regional rival Saudi Arabia of trying to destabilise the Islamic Republic through online propaganda campaigns.