An overcrowded bus carrying dozens of Buddhist pilgrims plummeted into a precipice in Sri Lanka on Sunday, killing at least 21 and injuring 24, a senior transport official said.

The island nation’s winding roads are among the most dangerous in the world, and the crash off a cliffside road on Sunday was among the deadliest recorded in Sri Lanka in decades.

The roof and side panels of the bus were sheared off, and more than half the seats were ripped from the floor of the vehicle, which landed wheels up into a tea plantation, photos of the wreckage showed.

The state-owned bus was carrying around 70 passengers — about 20 more than its capacity — through the central hilly region of Kotmale when the driver lost control and it veered off the road before dawn, police said.

“We are trying to establish whether it was a mechanical failure or if the driver fell asleep at the wheel,” a local police official told AFP, speaking on condition of anonymity because he was not authorised to speak to media.

Deputy Transport Minister Prasanna Gunasena told reporters at the scene that the injured were rushed to two area hospitals.

“Twenty-one have died and we are trying to identify the victims,” Gunasena said.

The toll could have been higher, the minister added, if not for local residents helping pull people from the mangled wreckage and rushing them to hospital.

Police said 24 people were being treated in the two hospitals.

One survivor told a local journalist that he had been in the front section of the bus and was lucky to have escaped with only minor injuries.

“The bus was leaning to the left side and as the driver was negotiating a bend, he lost control and it fell down the precipice,” said the man, who did not give his name, in a video seen by AFP.

The bus was travelling from the pilgrim town of Kataragama in the island’s deep south to the central city of Kurunegala, a distance of about 250 kilometres.

Sri Lanka records an average of 3,000 road fatalities annually, making the island’s roads among the most deadly in the world.

Sunday’s bus accident was one of the worst in the country since April 2005, when a driver attempted to beat a train at a level crossing in the town of Polgahawela. The bus driver was lightly injured, but 37 passengers were killed.

In March 2021, 13 passengers and the driver of a privately owned bus died when the vehicle crashed into a precipice in Passara, about 100 kilometres east of the scene of the crash on Sunday.