All the deceased were in two of the houses. Another five houses also suffered fire damage.
The tanker truck was travelling at high speed from Ho Chi Minh City to Binh Long town, Binh Phuoc province.
It crashed into a delivery tricycle which was carrying ice in the same direction at Minh Hung market and then hit a 220kv power pole on the opposite side of the road.
The truck flipped upside down in the crash, which caused tens of thousands of litres of oil to ignite.
Nine fire trucks and 65 firefighters were sent to the scene. The fire was controlled after three hours.
Competent agencies are investigating the incident.
