Officers received a tip that a large amount of illegal drugs would be smuggled from Myanmar into Thailand through Chiang Rai. Pol Col Pongsak Limchalermchat, deputy commander of Border Patrol Police Region 3, said he subsequently ordered police to keep a close watch on roads from the neighbouring country from Friday night.
On Saturday morning, he said, police spotted two pickup trucks, running from the border area along the Nong Mor-Rongkhun road in tambon Mae Kon of Muang district. They signalled the drivers to stop for a search.
But the two drivers refused to stop their vehicles and police had to fire gunshots into the air to force them to stop.
Police found 902,000 ya ba pills on the pickup trucks' back seats.
Arrested were Suchart Chodaku, 28, Arbue Seduku, 38 and Piratchai Wuisueku, 38.
The suspects told police that they had been paid to deliver the illegal drugs from Myanmar to Mae Kon sub-district.
After that, they said, other members of the drug trafficking gang would be further transporting the illegal drugs down to Bangkok and nearby Nonthaburi province.