Emergency services rushed to the scene as a bus burst into flames in Letterkenny on Thursday night.
A Bus Éireann Expressway bus - travelling from Letterkenny to Dublin - went on fire as it came around the Dry Arch roundabout at around 8.30pm.
Fifteen passengers and the driver had to flee before the flames shot around the vehicle.
All on board were able to evacuate retrieve their luggage and get to safety before the blaze took hold.
A Bus Éireann spokesperson confirmed that the vehicle was 'evacuated safely and the fire has been extinguished.'
Some passengers said those on board were aware that something was amiss.
"The driver tried to go on, but the bus started to smoke and someone ran for the side door when the bus was going around the roundabout," a witness told Donegal Live.
"The bus clearly wasn't working properly, although no-one expected it to go on fire."
Gardai, fire service and ambulance personnel attended the scene.
The roundabout, which serves as the main artery into Letterkenny, was closed.
Traffic diversions were put in place. Donegal Live understands that there were no serious injuries.
A Bus Eireann spokesperson told Donegal Live: "The vehicle will be cleared from the road shortly. A comprehensive and thorough investigation will be undertaken into the cause of this incident. This is an exceptionally rare occurrence in our fleet.
"Passengers have been accommodated on another vehicle to continue their journey.
"Bus Éireann would like to thank the emergency services, our driver and passengers for their rapid and effective response to the situation."
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