Five3 people were killed including the driver of a minivan after it was involved in a head-on smash Thursday morning in Sa Kaeo province.
The accident happened at around 10.50am on Suwannasorn Road in Watthana Nakhon with two men and two women pronounced dead at the scene, with a fifth person later dying in hospital.
Several other passengers, including two children, were taken to hospital.
Eyewitnesses told police a black Toyota lost control and veered across the road and smashed head-on into the minivan.
The Toyota driver will be questioned by police once he recovers from his injuries.