By Nattawat Laping
It included ammonium hydroxide and eight sacks of an unknown black powder from around 10 men who were leaving Thailand via the mountainous border in Chiang Rai's Mae Fah Luang district on Wednesday morning.
The authorities suspected that items were for drug manufacturing at a factory in Myanmar.
Officers had staked out Pang Mahan village in Tambon Terd Thai following a tip-off, said task force commander Colonel Chatree Sanguantham.
No suspects were arrested as the men fled into the forest, he said.