Iranian security forces arrested civilians Hadi Hassanvand and Peyman Yasmi in Abdanan, Ilam province, on 8 February.
Hassanvand was released after several hours of interrogation, but the fate of Yasmi remains unknown.
Yasmi’s brother, Pezhman Yasmi, was arrested by security forces in Abdanan on 23 December and is held in Ilam prison.
At least 14 civilians have been arrested by security forces over the past week following protests in Abdanan.