At around midday, the fire began at a conservation area for wetland birds, located 300 m from provincial road 843.
Tram Chim national park spans around 7,500 ha and is home to numerous rare bird species, including the Burmese Sarus flying crane from Cambodia.
In the 1900s, thousands of cranes could be seen at the national park, but their numbers have fallen over time. Dong Thap currently has projects to recover the numbers of these birds.
Columns of smoke, hundreds of meters tall, could be seen covering a large area of the park, including around 100 houses near it.
Smoke covers two houses on the side of provincial road 843. Authorities said people would be evacuated in a worst-case scenario. No casualties have been reported.
Bay Thum, 55, covers her nose with her clothes and gets to the back of her garden, located about 50 m from the fire.
"This area has seen fires from time to time, but this the largest, with the flames getting close to the garden," she said.
A fruit garden at the edge of the forest is painted in a yellow-orange hue due to the smoke and flames.
People used branches of plants and trees to try and put out some of the fires.
"The flames were so big and there were even explosions. They spread to a garden that is ready to be harvested," said Thum.