Erfan Rezaei was filmed tearing down a government poster showing the supreme leader shortly before he was killed on 21 September, the source said.Anti-government protests have engulfed Iran since the death in custody six weeks ago of Mahsa Amini, a 22-year-old woman who was detained by the morality police for allegedly wearing her hijab, or headscarf, "improperly".Iran's Human Rights Activists News Agency (HRANA) estimates that 248 protesters, including 33 children, have been killed by security forces.The source said Erfan died as a result of severe damage to the kidney and spleen caused by the bullet wound to his back.Last week, sources told BBC Persian that the family of Abolfazl Adinezadeh - a 17-year-old boy who was killed by a shotgun fired at point-blank range at a protest in Mashhad on 8 October - had been told to say he was a member of the Basij, a notorious paramilitary force involved in the crackdown."