Vietnamese officials at China border seized 19.8 kilograms of narcotics on Wednesday morning, but the two smugglers escaped.
Customs officials busted the smugglers at Mong Cai border gate in Quang Ninh Province at around 4 a.m., Vietnam News Agency reported.
The two smugglers jumped into the Ka Long River with the drug, which they left to flee during the chase.
On Monday afternoon, customs officers at Moc Bai border to Cambodia in Tay Ninh Province also arrested a 57-year-old woman carrying more than two kilograms of narcotics.
The officers checked her luggage over suspicious signs and found three black packages hidden inside a box of instant noodle packs.
The packages tested positive with narcotics.
Investigations into the cases are going on.
Vietnam has some of the world’s toughest drug laws.
Those convicted of producing or selling 100 grams of heroin or 300 grams of other illegal narcotics face the death penalty.
Smuggling more than 600 grams of heroin or more than 2.5 kilograms of methamphetamine is also punishable by death.