At least 16 people died and 23 more were injured on Thursday when a bus careened down an embankment near the Thai border as its transmission and brakes failed, according to police.

Hing Theung, police chief of Trapaing Prey commune in Oddar Meanchey’s Anlong Veng district, said the private bus from Phnom Penh, filled largely with elderly women, flipped over after crossing the border back into Cambodia via the Choam Sa-ngam border checkpoint.

“It was the failure of the gears of the bus,” he said, adding that the accident occurred at about 11:20am near Dangrek Mountain.

According to Pheung, 12 people died at the scene while four others died from their injuries at the local hospital. Another 23 remain hospitalized, with some in critical condition.

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.

On Monday, the Svay Rieng Provincial Court said it had concluded its investigation into that case and that bus driver Le Vang Phing, 43, would face trial later this month.

The most recent six-month report from the Ministry of Interior’s Department of Order showed 1,229 people killed and another 4,090 injured in the first half of 2015.