Heavy gunfire reportedly rang out at wards during a deadly blaze at the infamous Evin prison on Saturday night, according to reports from Iranian opposition outlets and social media accounts.
The fire at the prison in Tehran killed four inmates and injured a further 61, according to officials, who say the fire has since been brought under control.
Several reports on social media state that inmates heard gunfire as the nighttime blaze ripped through the prison.
IranWire, an opposition news website reported a revolt in wards 7 and 8 of the prison, and that gunfire had been reported by residents and neighbours around Evin prison "for a long time".
Twitter account 1500Tasvir, which has more than 41,000 followers, posted a series of tweets last night indicating that some of the prisoners were attacked at night by security forces, who opened fire on the inmates. They also reportedly beat prisoners and transferred them to an "unknown place", according to the account.
Other accounts reported that the security forces were blocking the highway while residents attempted to rescue some of the inmates.
Journalist Afshin Ismaeli posted a video showing a woman removing her hijab and waving it on the street leading to Evin prison, a traffic jam visible around her.
Evin prison is used by the Islamic Republic to detain political prisoners, many of whom are students, lawyers, artists, activists and intellectuals who have spoken out or expressed views against the regime. Many of those imprisoned during the recent protests in Iran are also jailed at Evin prison.
Iran has been engulfed by a wave of protests in the last month, sparked by the alleged killing of Mahsa Amini, a Kurdish-Iranian woman who was allegedly beaten to death by the country’s so-called morality police for wearing her headscarf 'improperly'.
These demonstrations have since morphed into a challenge against the Iranian regime, with protesters chanting against Supreme Leader Khamenei and his rule over the country.