"They put me on the ground, and an officer put his boot on my back. He kicked me in my stomach, tied my hands, picked me from my arms, and then pushed me into a van." This is how 51-year-old Maryam, a protester arrested last week in central Tehran, described the moment Iranian security forces detained her. Protests have spread across in Iran since the death on 16 September of Mahsa Amini, a 22-year-old woman who was detained by the morality police in the capital three days earlier for allegedly breaking strict hijab (headscarf) rules. Police maintain that she collapsed at a detention centre after suffering a heart attack, but her family allege that officers beat her head with a baton and banged her head against one of their vehicles. The protests sparked by her death, led mainly by women, began with demands to end the mandatory hijab laws. But they have now turned into nationwide demonstrations against Iran's leaders and the entire clerical establishment. 'Ruthless' commanders Despite widespread internet disruption, videos of protesters being arrested by the Iranian security forces have continued to be published on social media. "It is worse than what you see on these videos," said Maryam, which is not her real name. "I heard one of their commanders ordering their soldiers to be ruthless. The female officers are [just] as horrible. One of them slapped me and called me an Israeli spy and a prostitute." Other videos verified by the BBC appear to show security forces shooting live ammunition at protesters and arresting those they can catch. According to the state media, more than 40 people have been killed during the unrest. Human rights groups have reported a higher death toll. The overall number of people who have been arrested has not been shared by the authorities. However, the chief prosecutor of Mazandaran, a province north of Tehran, said at least 450 protesters had been detained there alone. Human rights groups say thousands of protestors are being detained. "I pushed a security officer back and tried to run away, but very soon, a second person and a third one arrived," said Sam, a young protester from a major city. "After a few seconds, more than 15 agents were beating me ruthlessly." He added: "I felt the taste of the blood in my mouth and the strikes of an electric stun gun on my body. They put me on the ground, tied my arms behind my back, and tied my feet with my shoelaces. "One of the soldiers kicked me in my left eye while taking me to [the place] where they kept the other detainees."