The fighting happened along the northern borders of Sistan and Balouchestan.
A military official identified the fallen soldier as Moein Ghadamyari. The official added that martyr was from the holy city of Mashhad.
Clashes between Iranian troops and bandits who infiltrate the Iranian territory from the eastern borders are commonplace.
Most of the armed gangs are narcotraffickers but some are also members of terrorist groups and enter Iran to carry out acts of terror.