At least 16 were killed and another 23 injured yesterday when a bus careened off an embankment in the Dangkrek Mountains as its brakes and transmission failed, police said.

Hing Theung, police chief of Trapieng Brey commune in Oddar Meanchey’s Anlong Veng district, said that at about 11:20am the 35-seat tourist bus and its 39 passengers ran off of the roadway and overturned as it returned from the Choam Sa-ngam Checkpoint on the Thai border.

Twelve of the victims died at the scene, while another four died in hospital.

“The driver, whose thigh was broken, said that the reason for the collapse was that when the vehicle came down the mountain, he could not control the gears and the brake system did not work, and the bus just overturned because it was going fast,” he said.

The bus’ passengers were travelling from Phnom Penh’s Dangkor district to hold a religious ceremony at Brasat Tamoan pagoda, and had briefly crossed the border beforehand.

“They visited Choam Sa-ngam Border Checkpoint and wanted to buy some products in a Thai market.

On the way back, they [were going] to have a religious march with candles to Brasat Tamoan Pagoda, and then the accident occurred,” he said.

Sem Vanak, Anlong Veng district police chief, said some of the injured were sent to the district referral hospital, while those with more serious injuries were sent to the Siem Reap Provincial Hospital.

“All the bodies are being brought by two [army] trucks to Phnom Penh,” he added.

Run Rothvesna, an official with the Ministry of Interior, blamed the driver for failing to ascertain that there was a problem with the vehicle before departing, and said many drivers in general are under-qualified, and lack drivers’ licences.

“The human factor . . . is still the primary cause of accidents,” he said.

The death toll is the nation’s largest since a deadly crash in Svay Rieng in May, which saw 18 garment workers killed as the minivan in which they were travelling collided head on with a speeding bus.

According to Ministry of Interior figures, 1,229 people were killed and another 4,090 injured in the first half of 2015.