Mohammad Ali Ahmadi, deputy governor in Ghazni province, says the victims had been kidnapped at various times, including while visiting their families.
Local residents found the corpses next to each other today in Andar district, their hands still chained behind their backs.
No group has claimed responsibility for the killings, but Taliban militants frequently target Afghan troops as part of their insurgency against the US supported government. Ahmadi says insurgents at times stop vehicles in search of people to "prosecute" for working for the government or security forces.