Protests began late last month over worsening economic conditions. But as the unrest spread to dozens of cities, demonstrators started targeting the political system as a whole. At least 21 people were killed and another 3,700 arrested, an Iranian lawmaker said Tuesday.
Amnesty International called on authorities to investigate reports that at least five people have died in custody following a crackdown on the protests. Three of those deaths took place in Iran's notorious Evin prison in the capital, Tehran, Amnesty said.
"The shroud of secrecy and lack of transparency over what happened to these detainees is alarming," said Magdalena Mughrabi, Amnesty's deputy director for the Middle East and North Africa. "The authorities must immediately launch an independent, impartial and transparent investigation, including independent autopsies."
Khamenei, speaking in the holy city of Qom, accused the United States and Israel of a "carefully organized" plot to overthrow Iran's government. He said "the enemy" had started chants against high prices, attracting Iranian demonstrators. But the nation soon rose up against the "enemies' conspiracy," according to a statement on the supreme leader's website.
The remarks were standard fare for Khamenei, who has presided over Iran's powerful clerical and security establishments for 29 years. He has long painted Western nations as enemies of the Islamic Republic.
"As expected, Khamenei has blamed foreign powers for the unrest in Iran," said Behnam Ben Taleblu, Iran expert at the Foundation for Defense of Democracies in Washington. "Iran's political elite are trying to dampen the very legitimate grievances that motivated people to pour into the streets."
Still, Khamenei acknowledged that hardships have led to discontent in Iran. He pointed to what he called "problematic financial institutions" as having left many Iranians "dissatisfied" with the economic situation.
A handful of illicit credit institutions have collapsed across Iran in recent years, wiping out deposits from ordinary Iranians. Many aggrieved depositors have staged protests outside banks and government offices, demanding to be reimbursed.
"Protests erupted when people couldn't withdraw their savings, but some figures in government suggested that the depositors should have known better," said Esfandyar Batmanghelidj, founder of Bourse & Bazaar, a website featuring economic analysis on Iran.
Iran's economy has struggled following years of U.S. and international sanctions, including those imposed because of the country's nuclear program. Many of the sanctions were lifted as part of a 2015 nuclear deal with world powers. But while Iran's renewed oil exports have boosted the economy, inflation and unemployment remain high.
"These appeals must be dealt with and heard out. They must be answered as much as possible," Khamenei said of the grievances. "I myself am responsible" for following up on the demands, he continued.
His remarks appeared to align with those made by President Hassan Rouhani on Monday. Rouhani urged the government and his hard-line rivals to recognize the demonstrators' demands.
Rouhani criticized those, however, who sought to portray the protests as concerned simply with economics. In that regard, he diverged from Khamenei, with whom the president has publicly sparred since his election to a second term in May.
"It would be a misrepresentation [of events] and also an insult to Iranian people to say they only had economic demands," Rouhani was quoted as saying by the Tasnim news agency, the Reuters news agency reported. "People had economic, political and social demands."