Five Laotian nationals were arrested when they tried to enter Vietnam on Friday with about 20 kg of heroin in their car.
The arrests were made near Tay Trang border gate in Dien Bien, a northwestern province bordering Laos, Tuoi Tre newspaper quoted Lieutenant Colonel Nguyen Duc Thang, commander of the Tay Trang Border Guard Station, as saying.
He said the five suspects are from the Lao province of Phongsali. One of them, Thao Phon, 47, is believed to be the ringleader.
He said the suspects and heroin were handed over to Lao authorities for further investigation.