The 45-seat bus was travelling from the Do Theatre towards central Nha Trang when a loud bang was heard and black smoke began rising from underneath the vehicle near Hon Chong at around 10.30 am.
The driver pulled over immediately, opened the doors and evacuated all passengers with their luggage. Within minutes, flames spread rapidly through most of the bus.
Firefighters dispatched two engines and dozens of personnel to the scene, where they extinguished the blaze in about 10 minutes.
The fire destroyed the bus, shattering windows and damaging some passengers' belongings. No injuries were reported.
Authorities are investigating the cause of the fire.