The two men were Pham Van Hiep, born in 1981 and Nguyen Truong Trung, born in 1992. They were arrested in Co Cham village, Long Luong Commune, Van Ho District, Son La Province.
Hiep is a convicted murderer while Trung has a previous robbery conviction.
In addition to the 30 bricks of heroin, the police also seized two motorbikes and other evidence.
The case is currently under investigation.