Moscow is rushing to the defense of its ally, suggesting that the unrest in Iran is no worse than clashes in the U.S. in recent years.
In Kermanshah, where the largest demonstrations took place, protesters shouted slogans against the Iranian leader Ayatollah Khamenei.
The recent Iranian elections changed the game. But the supreme leader remains firmly in control.
How long will it take for Supreme Leader Khamenei to undermine President Rouhani's democratic reforms?
Khamenei said sanctions imposed on Iran should be lifted as soon it reaches a final deal with major powers.
Ayatollah Ali Khamenei has broken his silence on the nuclear agreement.
"I neither support nor oppose the deal. Everything is in the details, it may be that the deceptive other side wants to restrict us in the details," Khamenei said in a speech broadcast live on state television.
Ayatollah Ali Khamenei has responded to overtures from U.S. President Barack Obama amid nuclear talks with a secret dispatch, The Wall Street Journal reported Friday.