BANGKOK - Eighteen people were killed and 31 others injured in a bus accident in eastern Thailand on Wednesday, authorities said.

The accident occurred early Wednesday in Prachinburi province when a double-decker bus carrying 49 people on a study tour lost control and overturned on a downhill road, the local public relations office said.

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According to a local road safety center, 49 people were on the vehicle when it flipped over at about 3:00 am local time, and 16 people were killed on the spot.

The injured people were taken to the nearest hospital for treatment.

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Local media quoted police as saying that the road was an accident-prone area. Preliminary investigations suggested that the accident may be caused by brake system failure.