Iranian security forces have arrested four figures within the country's reformist movement, state media reports.
A campaign of mass arrests and intimidation has led to the arrests of thousands as authorities seek to deter further protests after last month's crackdown on the bloodiest unrest since the 1979 Islamic Revolution.
On Sunday, detained Nobel Peace Prize laureate Narges Mohammadi received another prison sentence of over seven years.
Media reports quoted officials within the reformist movement, which seeks to change Iran's theocracy, as saying at least four of their members had been arrested.
They include Azar Mansouri, the head of the Reformist Front, which represents multiple reformist factions; and former diplomat Mohsen Aminzadeh, who served under reformist President Mohammad Khatami.
Also detained was Ebrahim Asgharzadeh, who led students who stormed the US 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 and have a transitional governing council oversee the country.
Iran's state-run IRNA news agency quoted a statement from prosecutors in Tehran, saying four people had been arrested and others summoned to meet authorities.
It accused those allegedly involved of “organising 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 cauterise dissent before it learns to walk.”
However, it remains unclear just how much political support reformists have within Iran. The anger on the streets of Iran during the January demonstrations, heard in people shouting “Death to Khamenei!” and in support of the country's exiled crown prince, appeared to lump reformists in with all other politicians now working in the Islamic Republic.
Iran and the US held new nuclear talks last week in Oman. Foreign Minister Abbas Araghchi, speaking on Sunday to diplomats at a summit in Tehran, signalled that Iran would stick to its position that it must be able to enrich uranium - a major point of contention with US President Donald Trump.
The US has moved the aircraft carrier USS Abraham Lincoln, ships and warplanes to the Middle East to pressure Iran into an agreement and have the firepower necessary to strike the Islamic Republic should Trump choose to do so.
Meanwhile, Iran issued a warning to pilots that it planned “rocket launches” on Monday into Tuesday in an area over the country’s Semnan province, home to the Imam Khomeini Spaceport. Such launches have corresponded in the past with Iran marking the anniversary of its 1979 Islamic Revolution.
with DPA and Reuters
