At least 40,000 liters of gasoline been leaked into the Tien River, a tributary to the Mekong River in Tien Giang Province, after a collision with a gas tanker on Tuesday.
The crash with a sand barge caused a cut of nearly three meters long on the right side of the tanker of state-owned fuel retailer Petrolimex, which was carrying 1.2 million liters of gasoline from Ho Chi Minh City to Cambodia.
No damage was incurred to the barge which was carrying more than 1,000 cubic meters of sand on the opposite direction.
Petrolimex has sent two boats to the site and they are expected to transfer all the remaining fuel from the damaged vessel by the end of Wednesday to prevent further gas spills and possible fire or explosion.
Police are investigating the cause of the collision.