The judicial authorities reported on its website on Sunday that the fire that broke out in Iran's Evin prison in Tehran overnight killed four detainees and injured 61 others.
IRNA reported on Sunday that the deaths were allegedly caused by smoke inhalation. Ten prisoners were hospitalised, with four being in "serious condition," IRNA added.
Iranians of mixed nationality are among the political detainees housed in the institution. According to their claims on social media, the relatives of roughly 20 political detainees have contacted to confirm that they are safe.
Western human rights organisations have long criticised the facility, and the US government placed it on a sanctions list in 2018 due to "serious human rights abuses."
The event happened as nationwide demonstrations following the death in custody of Iranian lady Mahsa Amini, 22, reached their sixth week.
“Officials here say there were clashes between prisoners and that some of those prisoners have set the fire in the warehouse, in the sewing workshop of the prison'', Sardar referred to an earlier comment made by Tehran Governor Mohsen Mansouri.