Iranian President Hassan Rohani says citizens are "absolutely free" to criticize the authorities and protest, but he warned against violence as demonstrations, unrest, and detentions continued for the fourth day in cities throughout the country.
Rohani’s comments on December 31 came as the authorities attempted to quell the unrest with warnings to protesters and by blocking popular social-media applications and disrupting some Internet services.
U.S. President Donald Trump continued to voice backing for protesters, calling out the authorities for having "closed down the Internet" and accusing them of violating the rights of those demonstrating on the streets.
"Iran, the Number One State of Sponsored Terror with numerous violations of Human Rights occurring on an hourly basis, has now closed down the Internet so that peaceful demonstrators cannot communicate. Not good!" Trump wrote on Twitter on December 31.
Actions on the streets of Tehran and other cities, including Sanandaj, Mashhad, Ilam, Khoramdareh, and Kermanshah, marked the biggest challenge to the authorities since violent demonstrations erupted after a disputed election handed Mahmud Ahmadinejad a second presidential term in 2009.
At least two protesters have reportedly been killed in this week's clashes, and hundreds have been arrested.
Rohani, in his first public remarks since the start of the protests, said Iranians had the right to protest, but he warned that those demonstrations should not make the public "feel concerned about their lives and security."
"The people are absolutely free in expressing their criticisms and even protests," Rohani said at a cabinet meeting, according to state-run Press TV.
"But criticism is different from violence and destroying public property," he added.
He also acknowledged the public's worries extend beyond the economy to corruption allegations and government transparency.
The initial protests were sparked by a surge in prices of basic food supplies, such as eggs and poultry.
They quickly spread to many cities where hundreds of protesters have been chanting slogans against the Islamic establishment and Iranian Supreme Leader Ayatollah Ali Khamenei.
Video and other information on social media showed protests taking place on December 31 in the capital, Tehran, and other cities, although crowd sizes were unclear.
Video footage appeared to show police in Tehran using water cannon to disperse demonstrators gathering in Ferdowsi Square in the center of the capital.
Officials said on December 31 that some 200 protesters in Tehran had been arrested the previous day.
Meanwhile, Iranian authorities have blocked popular social-media websites.
Users of the social networks Instagram and Telegram were unable to access the services on December 31.
Both applications are popular among Iranians and useful in helping set up gathering points for demonstrators who are disappointed with rising prices and Rohani’s unfulfilled promises to guarantee rights to freedom of expression and assembly.
"Iranian authorities are blocking access to Telegram for the majority of Iranians after our public refusal to shut down [Sedaie Mardom] and other peacefully protesting channels," Telegram Chief Executive Officer Pavel Durov said in a Twitter post from Dubai.
The United States has condemned the arrest of protesters, with Trump cheering on the protesters via Twitter.
Trump tweeted on December 31 that it looks like the Iranians "will not take it any longer," adding "The USA is watching very closely for human rights violations!"
Rohani criticized Trump over his tweets, saying he "has forgotten that he had called Iranian people 'terrorists' a few months ago."
Nikki Haley, the U.S. ambassador to the United Nations, was the latest U.S. official to comment on the unrest in Iran, saying Iran's government was "being tested by its own citizens."
"We pray that freedom and human rights will carry the day," she said in a statement on December 31.
Interior Minister Abdolreza Rahmani-Fazli warned earlier on December 31 that protesters who create unrest "are responsible for their actions and should pay the price."
The semiofficial news agency Mehr quoted Habibollah Khojastepour, deputy governor of Lorestan Province, as denying that security forces were involved in the fatal shootings "of our two dear citizens" in the western town of Dorudi on December 30.
"No shots were fired by the police and security forces. We have found evidence of enemies of the revolution, Takfiri groups and foreign agents in this clash," he added later on state television. Takfiri is a term used for Sunni militants, especially the Islamic State.
However, a video posted on social media purported to show two young men after they were shot dead by riot police, although RFE/RL could not verify the authenticity of the video,
The hard-line Revolutionary Guards and its Basij militia -- which led the crackdown against the 2009 protests -- so far has appeared to stay away from the demonstrations. However, in a statement carried by state media, it said, "The Iranian nation...will not allow the country to be hurt."
A video posted by VOA appeared to show Iranian special forces officers being deployed to the demonstrations in the capital, although it also could not be confirmed.
With reporting by RFE/RL's Radio Farda, The Guardian, VOA, Reuters, AFP, AP, and dpa