Iranian state TV says gunmen have killed two members of the Revolutionary Guard and wounded another two near the border with Pakistan.
State TV blamed the attack late on Saturday on "terrorists" without elaborating. The southeastern Sistan and Baluchistan province has been the scene of past clashes involving militants and drug smugglers.
In February, an Al Qaeda-linked group carried out a suicide car bomb attack against a bus carrying members of the Revolutionary Guard, killing at least 27 of them.
The Revolutionary Guard is an elite paramilitary group that is larger than the regular armed forces and answers directly to Supreme Leader Ayatollah Ali Khamenei, who has the final say on all state matters.