Thousands of Iranians protested in the restive southeast on Friday to mark a Sept. 30 crackdown by security forces known as “Bloody Friday” as the country’s clerical rulers battled persistent nationwide unrest.

Amnesty International said security forces unlawfully killed at least 66 people in September after firing at protesters in Zahedan, capital of flashpoint Sistan-Baluchistan province. Authorities said dissidents had provoked the clashes.

A video posted by the widely followed 1500 Tasvir activist Twitter account purported to show thousands marching again in Zahedan on Friday. The authenticity of the footage could not be verified.

Another video which 1500 Tasvir said was from the town of Khash in the southeast showed protesters trampling and breaking a street sign carrying the name of top general Qassem Soleimani, who was assassinated in a US drone attack in 2020 in Iraq.

Popular anger ahead of the Sept. 30 shooting was fueled by allegations of the rape of a local teenage girl by a police officer. Authorities have said the case is being investigated.

Anti-government demonstrations also started erupting that month after the death of a Kurdish woman, Mahsa Amini, who had been detained by morality police for allegedly flouting the Islamic Republic’s strict dress code imposed on women.