Authorities in the south central province of Binh Thuan on Sunday released five endangered sea turtles, previously caught by local fishermen, into the sea.
The name of the sea turtle species was not known, but an official at the provincial Department of Agriculture and Rural Development said it was a critically endangered species and protected under Vietnamese laws.
On Saturday, a group of inspectors from the department found the sea turtles under 3-meter-deep wells in the houses of Pham Van Toan and Chau Van Thuy of Phu Quy District.
The two residents hid the sea turtles in the wells with the intent to slaughter them.
Each of the turtles weighs around 80 kilograms.
Local authorities said it was the first time the sea turtle species were found on Binh Thuan's Phu Quy Island.
According to the World Wildlife Fund, five of the planet's seven sea turtles -- green sea turtle, hawksbill sea turtle, loggerhead sea turtle, olive ridley sea turtle and leatherback sea turtle -- are found in Vietnam and are in danger of extinction.