Three Iranian border guards were killed on Friday by unknown gunmen in a Kurdish area near the country's western border with Iraq.
The official IRNA news agency said the three were killed in clashes with “bandits” while patrolling near the town of Sardasht, located about 530 kilometers west of the capital, Tehran.
It said several of the attackers were also killed during the clash but did not elaborate further.
The area has seen occasional fighting between Iranian forces and Kurdish separatists, as well as militants linked to the extremist ISIS group.
Earlier in May, unknown gunmen killed three members of Iran's paramilitary Revolutionary Guard in a shootout that also took place in a Kurdish area.
Iran’s eastern border has been the scene of occasional clashes with Baluch militants.