CNN
 — 

At least four prisoners were killed and 61 injured after a fire at Evin prison in northern Tehran, Iranian state media IRNA reported, attributing Iranian authorities.

The prisoners died of smoke inhalation, IRNA added. The fire happened Saturday night and an Iranian security official said “thugs” set fire to the warehouse of prison clothing, IRNA reported earlier.

A large, dark plume of smoke was seen billowing near the prison in multiple videos on social media Saturday night.

The fire has been contained, and “peace is maintained,” the governor of Tehran, Mohsen Mansouri, told IRNA, adding that the fire was started by prisoners. Tehran’s Evin Prison is a notoriously brutal facility where the regime incarcerates political dissidents.

“Now the situation of the prison is completely under control and peace is maintained in the prison complex and the streets around the prison are being monitored and under control,” Mansouri said.

Activist group 1500tasvir reported that in videos posted on social media, gunshots were heard and Iranian special forces were seen heading to the area where the prison is believed to be located.

The Iranian official said that the “rioters” were separated from other prisoners and the other detainees have returned to their cells, IRNA reported. CNN cannot independently verify the situation.

Amnesty International Secretary General Agnes Callamard responded on Twitter to the social media videos with a reminder to Iranian authorities of their “legal obligation to respect and protect” the lives of prisoners following the fire.

Callamard noted the prison is “notorious” and retweeted a post from journalist Jason Rezaian whose “544 Days” podcast recounts the time he spent incarcerated in the prison.

“Evin is no ordinary prison. Many of Iran’s best and brightest have spent long stretches confined there, where brave women and men are denied their basic rights for speaking truth to power,” Rezaian wrote. “The regime is responsible for what happens to those inside right now.”

Speaking to state broadcaster IRIB, Tehran’s prosecutor Ali Salehi said the “conflict” at the prison was not linked to the protests that have swept the country following the death of a young woman in police custody.

In September, 22-year-old Mahsa Amini died after she was detained by the country’s morality police for allegedly not wearing her hijab properly. Iranian authorities have since unleashed a brutal crackdown on demonstrators, who have united around a range of grievances with the country’s authoritarian regime.

“Today’s conflict of prisoners has nothing to do with the recent riots, and basically, the ward related to security prisoners is separate and distant from the prisons of thieves and financial convicts where the fire and conflict took place,” Salehi said.

According to Tehran’s prosecutor, Wards 7 and 8 were overcrowded, and the main issue was the fire – which he said had been started by some prisoners. Both the prison and the surrounding streets are under control now, he said.

Witnesses previously said that Iranian security forces beat, shot and detained students at Tehran’s Sharif University. Last month, nearly two dozen children were killed during the protests, according to a report by Amnesty International.

At least 23 children – some as young as 11 – were killed by security forces in the last 10 days of September alone, the report said.

Earlier this week, an Iranian official also admitted that school students participating in street protests are being detained and taken to psychiatric institutions.