In total, it concerns almost 2,900 prisoners – some who have been completely pardoned and some who have received mitigated sentences, according to a decision attributed to the country's highest leader, Ayatollah Ali Khamenei. No names have yet been announced.
59 prisoners who have been sentenced to death have had their sentences converted to prison sentences, according to these reports.
The group also includes around 40 people who have been convicted of corresponding crimes against national security. 40 of the affected prisoners are described as foreign citizens.
Last summer, the Swedish Foreign Ministry was aware of four Swedish citizens being held in prison in Iran. One of them is the death-sentenced Swedish-Iranian researcher Ahmadreza Djalali, who worked at the Karolinska Institute in Stockholm.
Iran does not normally recognize dual citizenship.
In June, two Swedes, Johan Floderus and Saeed Azizi, were released as part of a prisoner exchange with Iran. In exchange, Sweden chose to release Hamid Noury, who was convicted of war crimes and complicity in the murder of thousands of political prisoners.
Iran's Ayatollah usually releases prisoners to demonstrate a kind of mercy in connection with religious holidays. On Saturday, the Prophet Muhammad's birthday will be celebrated.