Acting on a tip-off, narcotic suppression police followed a Chiang Mai-registered pickup truck which sped past a Tha Ko checkpoint on the Chiang Mai-Chiang Rai road in Mae Suay district.
According to information, people in the truck were to meet another group of people who followed them in another vehicle at a rendezvous in front of Mae Fa Luang University on Phahon Yothin road.
At the rendezvous point, police searched the first pickup and found 700,000 methamphetamine pills and 30kg of ice or crystal methamphetamine.
Five Hmong tribesmen, led by Saengsuri sae Lee, were arrested.
They allegedly confessed to having been hired by a group of Hmong people in Chiang Rai for 100,000 baht each to deliver the drugs to clients in Ayutthaya province. The drugs were to be distributed in Bangkok and nearby provinces.