The fire that broke out in Iran's Evin prison in Tehran overnight killed four inmates and left 61 others injured, the judicial authority said on its website Sunday.
"Four prisoners died due to smoke inhalation caused by the fire and 61 were injured," Mizan Online reported, adding that four of the injured were in "serious condition".
The four inmates who died in the fire "had been convicted of robbery and were serving their sentence in Evin prison," Mizan said.
Iran has been rocked by weeks of protests since 22-year-old Masha Amini's death was announced on September 16, three days after she was arrested by morality police in Tehran for allegedly violating the country's strict dress code for women.
Flames and a plume of smoke rose over the prison in Tehran's north, where some of those detained during the demonstrations over Amini's death in custody have reportedly been sent.
Citing the prison service, Mizan reported on Saturday night that the fire -- blamed on "riots and clashes" according to the authorities -- had been put out.
Earlier, the 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.
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 Islamic republic's 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.
- Families' concern -
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.
- 'Mullahs must get lost' -
Rights groups reported protests in solidarity with Evin detainees in Tehran late into the night, after angry demonstrators had taken to streets across Iran on Saturday despite internet cuts.
Young women have been at the forefront of the current wave of street protests, the biggest seen in the country for years.
"Guns, tanks, fireworks; the mullahs must get lost," women without hijabs chanted at a gathering at Tehran's Shariati Technical and Vocational College, in a video widely shared online.
Scores of jeering and whistling protesters hurled projectiles at security forces near a landmark roundabout in Hamedan city, west of Tehran, in footage verified by AFP.
Despite what online monitor NetBlocks called a "major disruption to internet traffic", protesters were also seen pouring onto the streets of the northwestern city of Ardabil in videos shared on Twitter.
Shopkeepers went on strike in Amini's hometown of Saqez, in Kurdistan province, and Mahabad in West Azerbaijan, said 1500tasvir.
There had been an appeal for a huge turnout for protests on Saturday under the slogan "The beginning of the end!"
"We have to be present in the squares, because the best VPN these days is the street," activists declared, referring to virtual private networks used to skirt internet restrictions.
- 'Riots' -
At least 108 people have been killed in the Amini protests, and at least 93 more have died in separate clashes in Zahedan, capital of the southeastern province of Sistan-Baluchestan, according to Iran Human Rights.
The unrest has continued despite what Amnesty International has called an "unrelenting brutal crackdown" that has included an "all-out attack on child protesters" -- leading to the deaths of at least 23 minors.
A Revolutionary Guards commander said Saturday that three members of its Basij militia had been killed and 850 wounded in Tehran since the start of the "sedition", state news agency IRNA said.
The crackdown has drawn international condemnation and sanctions against Iran from Britain, Canada and the United States.
European Union countries agreed this week to level new sanctions, and the move is due to be endorsed at the bloc's foreign ministers meeting in Luxembourg on Monday.
Iran's supreme leader has accused the country's enemies, including the United States and Israel, of fomenting the "riots".
In response to the protests, the clerical state's security forces have also launched a campaign of mass arrests of artists, dissidents, journalists and athletes.