The bus was travelling in Hamtic municipality in Antique province when the crash happened Tuesday afternoon, provincial disaster agency head Roderick Train told AFP.

Four Kenyan nationals were among the passengers, who were mostly residents of Antique, Governor Rhodora Cadiao told local radio station DZRH.

“I call that place ‘killer curve’… it was already the second Ceres bus that fell off there,” she said, referring to the bus company.

The heavily forested ravine was around 30 metres (100 feet) deep, Cadiao said.

Seven people, including one of the Kenyan nationals, were in critical condition in hospital and four others were stable, Train said, describing the section of road as “accident prone”.

The condition of the other two Kenyans is not clear.

“Based on the witnesses, it was a mechanical failure. The driver lost control, possible brake failure.”

Cadiao visited the hospital where survivors were being treated for their injuries. She promised government assistance for medical and funeral expenses of victims.

Train said the search and rescue operation had finished and authorities would now focus on retrieving the bus.

Deadly road accidents are common in the Philippines, where drivers frequently flout the rules and vehicles are often poorly maintained or overloaded.