Iran executed death row prisoners Saeid Geravand, Samad Geravand and Shahab Mansouri-Nasab in Qezel Hesar Prison in Karaj on 20 May.
The three prisoners, who were sentenced to death about four years ago in a joint drug case, were transferred to solitary confinement for execution on 19 May.
The night before the executions, the families of the three prisoners staged a sit-in protest outside the prison, but prison forces fired pellets and tear gas, injuring at least ten people.
Mansouri-Nasab was the father of one child, Saeid Geravand was the father of one child, and Samad Geravand was single. They came from the village of Sartarhan in Kuhdasht, Lorestan province.
Twice last year, the three prisoners were transferred to solitary confinement for execution, but the executions were suspended due to sit-ins and protests by their families outside the prison.