Iranian President Hassan Rouhani has addressed the nation for the first time since protests started across the country four days ago.
In a televised speech, Rouhani said that "people have the right to criticise" but not to cause disorder or destroy pubic property.
Iranian citizens are "completely free to express their criticism of the government or stage protests," he said, "in a way that would lead to the improvement of the country's conditions".
However, he warned that authorities would not tolerate antisocial behaviour.
Iran has restricted social media networks that have been used to organise the anti-establishment demonstrations.
State news agency Irib said temporary restrictions on the Telegram and Instagram apps were imposed to "maintain tranquillity".
US President Donald Trump tweeted his support for the protestors, saying "the people are finally getting wise as to how their money and weath is being stolen and squandered on terrorism."