Warning: The following story contains graphic details of violence which some readers might find upsetting. A BBC Persian analysis of hundreds of videos and photographs taken during recent protests in Iran confirms the security forces' use of a wide range of weaponry, including machine guns, sniper rifles, and shotguns. Protesters were reportedly killed in many of the more than 200 cities where protests had been recorded. While the exact death toll remains unclear, the level of brutality and deployment of lethal weaponry evidenced in pictures, witness accounts, and reports by human rights groups and the media show thousands have been killed across the country. The crackdown on protests, which began over the economy, but rapidly escalated, employed a level of violence unprecedented in modern Iranian history. This is the largest mass killing in contemporary Iranian history and one of the largest in the world, says Payam Akhavan, an Iranian Canadian former UN prosecutor at the International Criminal Court in The Hague. The Iranian government has blamed the killings on rioters and terrorists. But the analysis shows security forces used various weapons against protesters, including machine guns, sniper rifles, shotguns, handguns, pellet-firing paintball guns, tear gas, machetes, knives, batons, large wooden clubs, and blinding green laser sights. Footage from cities such as Tehran, Isfahan, Yazdanshahr, and Shahsavar confirms both heavy and medium machine guns were employed for crowd control. Reports indicate that both lethal and non-lethal methods were exploited in an attempt to suppress dissent, with many facing life-altering injuries from rubber bullets and shotguns during the protests. The sheer scale of violence has provoked outrage and severe condemnation from human rights organizations worldwide.