Firefighters are tackling a blaze at Evin prison in the Iranian capital, Tehran, which holds political prisoners, as shots and an alarm could be heard on Saturday. State media quoted a security official, who was not named, who said the situation at the prison was “calm” after unrest in a section of the jail holding “thugs”. The first reports of gunfire were at 7.30pm local time as protests continue to sweep across the country. “Gunshots can be heard from Evin prison and smoke can be seen,” reported the activist website 1500tasvir, which also shared video footage it said showed special forces on motorbikes heading for the prison. A witness told Reuters: “Families of prisoners have gathered in front of the main door of Evin prison. I can see fire and smoke. Lots of special forces. Ambulances are here too.” British-Iranian dual national Nazanin Zaghari-Ratcliffe was incarcerated at Evin prison for almost five years. She was arrested in 2016 on spying allegations, charges which she has always denied, and finally returned home to the UK in March this year after a six-year ordeal. Anoosheh Ashoori, a British-Iranian retired engineer, was jailed in Evin for nearly five years after being accused of spying for Israel, charges he always denied. He was freed at the same time as Zaghari-Ratcliffe. Siamak Namazi, an Iranian-American imprisoned in Iran for nearly seven years on espionage-related charges rejected by Washington as baseless, returned to Evin on Wednesday after being granted a brief furlough, his lawyer said. Other dual nationals are also held at Evin. The prison, which mostly holds detainees facing security charges, has long been criticised by western rights groups and was blacklisted by the US government in 2018 for “serious human rights abuses”. Human Rights Watch has accused authorities at the prison of using threats of torture and of indefinite imprisonment, as well as lengthy interrogations and denial of medical care for detainees. Last year, Amnesty International said leaked surveillance footage from the prison showed prisoners being abused and sexually harassed. Protests in Iran first broke out last month after the death of Mahsa Amini, 22, in police custody. Mahsa became a symbol of Iranian repression after her arrest by the morality police, who accused her of wearing her hijab improperly. Protests have widened to strikes as shops and businesses closed in response to the country’s religious rule.