Iran's Atomic Energy Organization said Sunday an email server of its subsidiary was hacked in a "foreign" attack it claimed was aimed at drawing "attention" amid protests over the death of Mahsa Amini, AFP reported.
A wave of unrest has rocked Iran since Amini, 22, died on September 16 after her arrest by the morality police in Tehran for allegedly violating the Islamic Republic's strict dress code for women.
The street violence has led to dozens of deaths, mostly of protesters but also members of the security forces.
A group called Black Reward on Friday issued an ultimatum on Twitter, threatening to release documents on Tehran's nuclear program unless all "political prisoners, prisoners of conscience and people arrested in the recent protests" were released within 24 hours.
Material on social media said to be released by the group on Saturday included a short clip from a purported nuclear site in Iran, as well as documents containing agreements, maps and payslips.
The nuclear agency acknowledged in its statement on Sunday that a hack had targeted its subsidiary, the Atomic Energy Production and Development Company, but downplayed the importance of the documents.
"Unauthorized access by a source originating from a specific foreign country to the email system of this company led to the publication of the content of some emails on social media," it said in a statement quoted by AFP.
These emails contain "technical messages and normal and daily exchanges", it added.
"The purpose of such illegal efforts, which are made out of desperation, is to attract public attention, creating media atmospheres and psychological operations," the statement continued.
The hacking comes as indirect talks between the US and Iran on a return to the 2015 nuclear deal appear to be stalled.
Iran recently announced it had submitted its comments to the US response to the European Union’s draft for reviving the 2015 Iran nuclear deal.
While Iran’s Foreign Ministry spokesperson said at the time that Iran’s response was prepared based on a constructive approach, a senior Biden administration official told Politico, “We are studying Iran’s response, but the bottom line is that it is not at all encouraging.”
A US official said late last month that the efforts to revive the 2015 Iran nuclear deal have “hit a wall” because of Iran's insistence on the closure of the UN nuclear watchdog's investigations.
Last week, White House press secretary Karine Jean-Pierre said that while negotiations to revive the 2015 Iran nuclear deal continue, the Biden Administration does not expect a new deal will be reached "anytime soon".