Police stated on Sunday (May 12) that a bus carrying high school students on a graduation trip crashed on Indonesia's largest island, killing at least 11 people and injuring numerous more.

The bus was carrying more than 60 students and teachers from the Java island town of Depok to Lembang, a popular tourist spot, when it crashed at 6.48pm on Saturday.

The students had just celebrated their graduation and were on a school trip when the bus suddenly lost control and tilted to the left, crashing into a car and three motorbikes, West Java province police spokesman Jules Abraham Abast told AFP on Sunday.

"Out of the passengers who died, nine of them were students, and one of them was a teacher," Abast said.

The accident also killed one motorcyclist, seriously injured 13 people and caused minor injuries to 40 others, he added.

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