The gas truck lost control at 12.30am near an intersection in Nong Ki district and slid into the other truck. The crash generated a massive explosion to start with.
The gas then fuelled the spread of the fire around the area, which was shaken by further explosions, forcing everyone who lived nearby to run for their lives.
More than 50 fire trucks battled to extinguish the huge blaze before it expanded to other areas.
Rescuers had to rush the injured to hospital.
It took three hours to control the fire and a 5km-radius of the area around the explosions was closed.
The drivers of both the gas truck and the 18-wheeler miraculously survived after jumping out of their vehicles in the nick of time just before the explosion.