Fifteen Indonesians were killed on Sunday when an inter-city bus lost control due to a brake failure on Sumatra island, police said, adding that the death toll may rise.
The bus was carrying 37 people when it tried to overtake two cars in front of it on a narrow ascending road, police official Ardiyanto told AFP.
One of the cars stopped abruptly and the bus, due to a brake failure, slid down into a ravine, he said.
"The number of casualties may rise as there are ten passengers that are badly injured," he said, adding that the accident took place at 2pm (0700GMT) in the Lembah Anai area of Padang Panjang city in West Sumatra province.
Fatal road accidents are common on Indonesia's poorly maintained roads.