The Black Rewards tweeted images of sensitive internal communication documents of Iran's Nuclear Power Production and Development Company and threatened to release the information unless the Islamic Republic released all detained protesters. 

It also threatened to publish documents that would affect the "dirty nuclear project of the mullahs' regime," according to the statement issued by the group.

As protests continued in various Iranian cities, the National Council of Resistance of Iran announced that the protests in Iran had killed more than 400 people among the demonstrators.

Humanitarian organizations have expressed fear that Iranian activists arrested during the crackdown on protests sparked by Zhina Amini's death risk torture or even death behind bars.

Amini died at 22 in September, three days after Tehran's morality police arrested her for violating the Islamic Republic's strict dress code, which sparked protests that have been going on for more than a month.

Black Reward, sometimes called hacktivists, have been active in their protest against Iran and have used the means at their disposal to target state institutions. Several other cyber groups, including Anonymous, have launched cyberattacks on Iran's government since the unrest began, which is the longest-lasting protest to date.

The group emailed Iranian authorities through Iran’s Nuclear Power Production and Development Company email system that demanded the release of detainees and ended with the phrase “A Free Iran,” and closed with “Jin, Jiyan Azadi for Zhina Amini."

Copy of the email send to Iranian authorities