A fire and clashes erupted at Tehran's notorious Evin prison Saturday night as the protest movement sparked by Mahsa Amini's death in custody entered a fifth week.
The facility in northern Tehran is infamous for the ill-treatment of political prisoners and also holds foreign detainees. Hundreds of those detained during the demonstrations over Amini's death have reportedly been sent there.
Flames and a plume of smoke could be seen billowing into the night sky, and the sound of what appeared to be gunfire could be heard in video footage shared on Twitter by the Oslo-based Iran Human Rights.
"A fire is spreading in Evin prison" and an "explosion was heard" from the facility, the 1500tasvir social media channel, which monitors protests and police violations, said on Twitter.
Chants of "Death to the dictator" -- one of the main slogans of a month-long protest movement that has flared over the death of Amini -- could be heard in the background of the video, AFP reported.
Amini, 22, died on September 16, three days after falling into a coma following her arrest by Iran's notorious morality police over an alleged breach of the strict dress code for women.
Iranian state media said early Sunday that the fire caused during "riots and clashes" at the prison had been extinguished.
Citing a Tehran prosecutor, the IRNA news agency said the situation was now calm and that the clashes had "nothing to do with the recent unrest in the country". IRNA earlier reported at least eight injured at the jail.
Evin prison holds foreign inmates including French-Iranian academic Fariba Adelkhah and US citizen Siamak Namazi, whose family said he was taken back into custody this week after a temporary release.
Reacting to reports of the fire, Namazi's family said in a statement to AFP shared by their lawyer that they were "deeply concerned" and had not heard from him.
They urged Iran's authorities to grant him "immediate" means to contact his family and to grant him a furlough "as he clearly isn't safe in Evin Prison."
The sister of another US citizen held at Evin, businessman Emad Shargi, said his family was "numb with worry" in a Twitter post.
Australian academic Kylie Moore-Gilbert, who was held in Evin for most of her 800-plus days behind bars in Iran, said she had heard all the women political prisoners were safe.
"I recently received word from two different family members of political prisoners currently inside," Moore-Gilbert, who was released in November 2020, told AFP early Sunday.
"They assure me that all of the women within the female political prisoner ward of Evin are safe and unharmed."
US State Department spokesman Ned Price said Washington was monitoring the incident "with urgency", warning that Iran was "fully responsible for the safety of our wrongfully detained citizens" and calling for their quick release.
Award-winning dissident Iranian filmmaker Jafar Panahi and reformist politician Mostafa Tajzadeh are also reportedly held at Evin.