Iranian authorities have moved to arrest a large number of reformist figures critical of the government. After last month’s bloody suppression of anti-government protests in Iran left thousands dead, criticism of the authorities grew even within reformist ranks, and the move is seen as an attempt both to tighten internal control and to emphasize the regime’s durability amid nuclear talks with the United States.

On the 9th (local time), the New York Times (NYT) reported that at least seven opposition figures, including Azar Mansouri, head of the Reform Front, a coalition of Iran’s reformist parties, had been arrested. The Reform Front is an alliance of political forces within Iran’s theocratic system that call for gradual reform. As the violent crackdown on recent anti-government protests intensified and reformist figures raised the volume of their criticism, the authorities expanded their repression.

Mansouri, who leads the Islamic Iran People’s Party Union (UIIPP), is a reformist politician involved in advancing women’s rights and civic activism. On the 26th of last month, demanding a fact-finding investigation into the authorities’ bloody suppression, she declared, “We will never allow the blood of these precious people to be forgotten or for the truth to be buried in the dust.”

Among those arrested were veteran politician Ebrahim Asgharzadeh, who led the 1979 U.S. Embassy takeover, and Hossein Karroubi, the son of reformist leader and former prime minister Mehdi Karroubi, who has been under house arrest for 14 years. Karroubi was recently identified as the person behind drafting and distributing a government-critical statement issued by his father.

Mohsen Aminzadeh, who served as a deputy minister at the Ministry of Foreign Affairs under reformist President Mohammad Khatami, was also detained. The UK-based outlet IranWire noted that this shows even former senior officials are not free from the risk of arrest.

The NYT reported that the Reform Front had been drafting a statement urging Iran’s Supreme Leader Ayatollah Ali Khamenei to resign and to prepare a transitional governing council to transfer power to the president. An audio file from a meeting of the coalition’s senior leadership discussing this was also circulated on social media.

Prosecutors in Iran said the detainees face charges of “organizing and leading activities aimed at disrupting the country’s political and social situation amid military threats from the United States and the Zionist regime (Israel).”

The arrests are expected to deal a political blow to President Masoud Pezeshkian, who was elected with the support of the Reform Front. The BBC pointed out that, within Iran’s theocratic system, both President Pezeshkian’s personal standing and the inherent weakness of the presidency have once again been exposed.

The BBC also noted that the arrest of reformist figures just days after U.S.-Iran nuclear talks resumed in Oman on the 6th shows that hardliners still hold real power inside Iran.

Ali Vaez, senior Iran analyst at the International Crisis Group, told the NYT that the fact these arrests of reformist figures took place as nuclear talks with the United States resumed “shows the regime is willing to fight for its survival at any cost,” adding that “it is sending a signal that it will tolerate no form of dissent at home, whether from the general public or the political elite, and a message abroad that it still maintains formidable control.”

The U.S.-based Human Rights Activists News Agency said that 6,964 people were killed in the protests. The UK-based opposition outlet Iran International estimates that the death toll is over 36,500.