Police Col. Surachet Thopunyanon said a joint military-police force found 2.5 million methamphetamine tablets and 50 kilograms (110 pounds) of crystal meth Friday at a house in Chiang Rai, Thailand's northernmost province bordering Myanmar and Laos. He said one Thai man and two Thai women were arrested.
Thailand is a leading market and transit point for methamphetamine, much of it produced in Myanmar.
The year's biggest seizure of more than 4 million tablets was made at a checkpoint in Chiang Rai two weeks ago. About 2 million tablets were seized Thursday in the northern province of Lampang.