Ngo Thi Thanh Mai, 20, from Ba Ria-Vung Tau province; Nguyen Xuan Hai, 45, from Dong Nai province; Bui Minh Bao, 45, from HCM City; and Vuong Quoc Thai, a Vietnamese Australian were carrying the drugs by car when they were stopped.

They were heading for HCM City, the police said. Further investigations into the case are underway.

Traffickers often bring drugs by motorbike at night across the border into Vietnam, and flee into Cambodia when accosted by authorities.