Four people died and two others injured after the pickup truck they were travelling in crashed into a roadside tree in Tha Song Yang district of Tak province late Tuesday night.
Mae Moei station police said the incident happened near Kilometre 112 on Highway 105.
Rescue workers from Tha Song Yang Phetkasem Foundation rushed to the scene first and they reported three on the spot and three others injured.
They were immediately rushed to Mae Song hospital.
One was pronounced dead on arrival.
Police said the driver might be on drowsy driving as the truck slammed into the tree by the roadside at high speed, throwing all out of the vehicle.