A Frontier Corp spokesman said the convoy was targeted in Awaran district when the personnel were returning after an encounter with militants linked to the Baluch Republic Army.
"It was a targeted attack on the convoy," he said.
The spokesman said the security forces had killed three militants, including an important local commander, in Barkhan area earlier in the day.
A sub-machine gun, two rifles and hand-grenades were seized from the militants, he added.
