Also detained was Ebrahim Asgharzadeh, who led students who stormed the U.S. Embassy in Tehran in 1979, sparking the 444-day hostage crisis.
Their arrests likely stem from a reformist statement in January that called for Iran's 86-year-old Supreme Leader Ayatollah Ali Khamenei to resign from his position and have a transitional governing council oversee the country.
Iran's state-run IRNA news agency quoted a statement from prosecutors in Tehran, the country's capital, saying four people had been arrested and others summoned to meet authorities. It accused those allegedly involved of "organizing and leading ... activities aimed at disrupting the political and social situation in the country amid military threats from the United States and the Zionist regime."
"Having bludgeoned the streets into silence with exemplary cruelty, the regime has shifted its attention inward, fixing its stare on its loyal opposition," wrote Ali Vaez, an Iran expert at the International Crisis Group.
"The reformists, sensing the ground move beneath them, had begun to drift - and power, ever paranoid, is now determined to cauterize dissent before it learns to walk."