The owner of the bus that caught fire and killed 23 students and teachers in Pathum Thani tried to hide some gas cylinders on other buses in the same fleet, according to the Department of Land Transport.
After the company failed to send five buses for inspection on Thursday as ordered, officials found them via GPS at a garage in Nakhon Ratchasima and seized them while their gas cylinders were being removed, the department said.
Additional cylinders that had been illegally installed on the buses were being removed at the garage, the department said.
The five buses were part of a six-bus fleet which included the bus that caught fire and killed 20 students and three teachers from Uthai Thani during a field trip on Tuesday.
The bus involved in Tuesday’s tragedy had been in service for more than 50 years and had been modified multiple times. It had been refitted to use gas but the installation was not up to standard. The licence of its Sing Buri-based operator, Chinnaboot Engineering (Thailand) Co, has been suspended pending further investigations.
Police said the bus had more cylinders than permitted and there was clear evidence of wrongdoing.
Investigators found 11 gas cylinders in the bus but only six had been legally installed and certified by land transport authorities.
Forensic police have determined that gas had leaked out before the fire but they have yet to determine conclusively how the fire was started.
