Police investigators identified the two officers who died from the incident on Highway 1A in the district of Ham Thuan Nam in the town of Thuan Nam, as senior lieutenant colonel Nguyen Viet Lien, 57, and Major Nguyen Tien Ich, 37.
Investigators said that the two officers who died were riding in a police transport vehicle along with two other officers when it was struck from behind and crushed by the larger rig.
The other two officers were seriously injured and transferred to a local hospital for emergency treatment. The driver of the truck, Do Ngo Chien, was not injured.
The investigation of the accident remains ongoing.