Police seized about 600 kilogrammes of methamphetamine and arrested the driver and attendant of a chartered bus taking students on a field trip.
Informants led police to arrest Amorn Chatawittayakul, the 53-year-old driver, and bus attendant Naratorn Hongtong, 20, at Tha Yang intersection on Phetkasem Highway in Tha Yang district about 8pm on Thursday.
They seized about 30 sacks containing speed pills and crystal meth from the luggage compartment of the bus, which bore the logo of Patcharee Tour. Each sack weighed about 20kg.
The suspects told police that a southern school had chartered the bus, registered in Songkhla province, to take students to the King Mongkut Memorial Park of Science and Technology in Prachuap Khiri Khan province.
While the students were at the park, they drove the bus to Pak Tho district of Ratchaburi to pick up the sacks from a man who was paying them 100,000 baht to deliver them to Phatthalung province.
They then went back to the park and, at the appointed time, picked up the students for their return trip.
As they headed south, the bus was stopped and searched in Phetchaburi and the two crew arrested.