Coast guards in the northern province of Nam Dinh seized a Myanmarese vessel Tuesday for smuggling diesel oil into Vietnam.
The patrolling coast guards approached two suspicious-looking vessels some 21 nautical miles southeast of the Ninh Co estuary.
Upon raiding the boats, they found crew members transferring diesel oil to a Vietnamese boat.
All crew members were taken to Hai Thinh Port for questioning, while the ship's oil was seized.
The boats' crew members confessed to being involved in the illegal oil trade.
The Vietnamese boat with seven crew members was about to buy more than 5,000 tons of diesel oil from the Yong Win 18.
In addition to the Myanmarese ship's captain, there were 16 sailors 14 Burmese and two Chinese onboard.
The case is being investigated further.