The soldiers were being dispatched to take part in military exercises in the Moscow-backed region when the vehicle's brakes failed outside the city of Tskhinvali, the defence ministry told local news agencies.
"As a result of a traffic accident, six officers were killed and 16 suffered injuries," news agencies quoted the ministry as saying.
The defence ministry declined to provide further details when contacted by AFP.
In August 2008, Georgia fought and lost a brief war with Russia over the Kremlin-backed separatist region of South Ossetia.
Georgia has decried Russia's "creeping annexation" of its territory, accusing Russian border guards of moving South Ossetia's border markers further into Tbilisi-controlled area.