Lo Van Dung, 31, a Vietnamese national, was caught last Friday in the Houaphanh Province at the Vietnam-Laos border. He was transporting 9.9 kilograms of heroin from the Lao province to the central Vietnam province of Thanh Hoa.

While expanding the investigation, police caught Thao Dia Tho, 20, a Lao national, the next day with 660 grams of heroin.

The two men and the seized drugs will be handled by Lao authorities.

Vietnam is a key trafficking hub for drugs from the Golden Triangle, an intersection of Laos, Thailand and Myanmar, which is the world's second largest drug producing area after the Golden Crescent in South Asia.

Drug trafficking and consumption have persisted and worsened in Vietnam over the last few years, despite the country having some of the world's toughest anti-drug laws, including death sentences for drug smuggling and trading.