At least ten people have been killed in four days of demonstrations in Iran, state media reported, in the biggest wave of unrest in the country since mass protests in 2009.
The violence continued despite an appeal for calm by Iranian president Hassan Rouhani on Sunday night. He is expected to address the nation again on Monday, as the country's leadership struggles to respond to the largely spontaneous uprisings that began on Thursday.
Iran's state broadcaster said six people were killed in the small western town of Tuyserkan, according to Agence France-Presse (AFP).
Two were shot dead in the southwestern city of Izeh, the area's local member of parliament, Hedayatollah Khademi, told the semi-official ILNA news agency. Khademi said he did not know whether the shots were fired by security officials or protesters, according to the report.
Izeh is in the oil-rich southern province of Khuzestan, just south of the Lorestan province where two other Iranians were killed in protests on Saturday evening.
The deputy governor of Lorestan province, Habibollah Khojastehpour, denied that security forces had fired any bullets, blaming "Takfiri" groups and foreign intelligence services for the clashes.
Another two people were killed Sunday in the city of Dorud after a fire engine was hijacked, the semi-official ISNA news agency reported, citing the local governor.
In a pre-recorded appeal for calm aired on state TV Sunday, President Rouhan said that while Iranians had the right to criticize authorities, the government would show no tolerance for those stoking unrest.
"We are a free nation, and according to the constitution and citizen rights, the people are free to express their criticism and even their protests," Rouhani said.
"But criticism should not be accompanied with violence or vandalizing public property." Rouhani also acknowledged public concerns over the economy and corruption.
Earlier, state-run media outlet IRIB reported that Iranian officials had temporarily restricted access to social media apps Instagram and Telegram, which have been used by Iranians to share news about the protests. Iran's Minister for Communications and Technology Azari Jahromi denounced the reports as "rumors" in a post on Twitter Monday.
Social media has helped galvanize tens of thousands participating in the protests -- described as the largest public display of discontent in Iran since the 2009 Green Movement, when people took to the streets to dispute the election of President Mahmoud Ahmadinejad.
The recent unrest stemmed from discontent over rising food and fuel prices, but has boiled over into a nationwide outcry against the government. In a rare act of defiance, some protestors have even called for the resignation of Supreme Leader Ayatollah Khamenei.
Video shared on social media captured Iranians chanting "We don't want an Islamic Republic" and "Death to the dictator." CNN has not independently verified the authenticity of the footage, purportedly shot in the western city of Khorramabad.
US President Donald Trump voiced his support for the demonstrations in a series of tweets on Sunday. He posted: "The people are finally getting wise as to how their money and wealth is being stolen and squandered on terrorism. Looks like they will not take it any longer. The USA is watching very closely for human rights violations!"
Rouhani, who won re-election in May, said in his speech that Trump had been at the root of many of Iranians' woes, "constantly creating problems" for people in the country since he entered the White House.