Bueng Kan provincial governor Nirat Pongsitthithaworn identified them as Boonyung Namthaisong, 41, Yonlada Wilaichit, 35, Rachan Sombatdee, 22, and Napida Srichuen, 19.
Nirat said the four were arrested on Wednesday after they travelled in a pickup truck from Laos via a border checkpoint in Ban Haad Hae, Tambon Khok Kwang.
The governor said the four tried to speed away but police and troops caught them up. Nirat said the suspects tried to throw away the drugs from their truck but the authorities managed to retrieve the evidence.
Napida reportedly told police she bought the drugs from a Lao man to sell in Bueng Kan but the three other suspects denied knowing anything about the deal.