The bus slammed into cars and motorbikes after its brakes apparently malfunctioned while returning from a graduation trip, killing at least 11 people, many of them students, and injuring dozens of others.

A bus carrying high school students and teachers returning from a graduation celebration crashed in the Indonesian province of West Java, killing at least 11 people and injuring dozens of others, officials said on Sunday.

The bus carrying 61 students and teachers was returning from the hilly resort area of Bandung to a high school in Depok, located outside the capital Jakarta, when it crashed at 6:48 p.m. local time on Saturday.

The students had just celebrated their graduation and were on a school trip when the bus suddenly lost control on a downhill road and crossed lanes, crashing into several cars and three motorbikes before it crashed into an electricity pole, West Java police spokesman Jules Abraham Abast said Sunday.

Nine students died at the scene and two others, including a teacher and a motorcyclist, died later in the hospital, Abast said. Fifty-three other people were hospitalised with injuries, including 13 in critical condition, he added.

Eighteen surgeries for serious injuries have been carried out so far, a West Java police commissioner told reporters on Sunday.

Local traffic police chief Undang Syarif Hidayat told broadcaster Kompas that he suspected the bus’ brake malfunctioned before the crash, but Abast said police were still investigating the cause of the accident.

A preliminary investigation revealed that the bus was apparently not fit for the road and had malfunctioning breaks.

Local television footage showed the mangled bus in the darkness on its side, surrounded by rescuers, police, and passersby as ambulances evacuated the injured.

Deadly road accidents are common in Indonesia, where vehicles are often old or poorly maintained, and road rules are routinely ignored. Hilly terrain and inadequate road lighting in the country also cause hazardous driving conditions that lead to regular crashes.

At least 12 people were killed last month after a car crashed into a bus and another car on a busy highway in West Java as people travelled to celebrate Eid-al-Fitr with relatives at the end of the Islamic holy month of Ramadan.

Last year, a tourist bus with a drowsy driver slammed into a billboard on a highway in East Java, killing at least 14 people and injuring 19 others.

In 2021, a tourist bus plunged into a ravine in the West Java hilly resort of Puncak after its brakes apparently malfunctioned, killing at least 27 people including middle school students who were on their way home from a school trip and injuring 39 others.