A senior commander of Iran's Islamic Revolutionary Guard Corps escaped unhurt when gunmen attacked his convoy in the country's restive south-east on Saturday, state media said.
A bodyguard of Brig Gen Hossein Almassi was killed in the attack at a checkpoint in Sistan and Baluchestan, the Irna news agency said.
The slain bodyguard was identified as Mahmoud Absalan, the son of Gen Parviz Absalan, a commander of the IRGC in the region.
State television said "criminals" had opened fire at the checkpoint, at the entrance to the provincial capital of Zahedan.
Irna said security forces arrested those behind the attack.
The attack came two days after Iran announced the arrest in Sistan and Baluchestan of three people it said were linked to Israel's Mossad spy agency.
Poverty-stricken Sistan and Baluchestan is a flashpoint for clashes with smuggling gangs, as well as separatists from the Baloch minority and extremist militant groups.
In January, state media said three IRGC members were among nine people killed in a clash with "armed criminals" in the province.
And in November, Irna said three members of the security forces were killed in similar circumstances.
At least 20 people were reported killed in the bombing of a bus carrying paramilitary forces in Sistan and Baluchestan in February 2019. State media said the attack was claimed by Jaish Al Adl (Army of Justice) militant group.
With reporting from agencies