The NFRS told Nauru Media News that their investigations into the fire last Friday indicate arson.
Officers from NFRS responded to a call about a fire on a bus which was full of rubbish in Boe.
The fire also burnt coconut trees nearby.
The Fire and Rescue Services is urging residents to refrain from burning anything without first securing the area to burn by cleaning the surroundings in case the fire spreads, especially in a close residential area.
This caution has been issued in light of the prolonged dry spell and strong breeze during this time on the island.
Photo Nauru Media News