According to China Central Television, among the passengers there were students who were scheduled to take the gaokao - the national college entrance exams - on Tuesday and Wednesday.

Beijing Youth Daily cited a staff member of the city government of Anshun and said the No 2 bus is an urban bus that stops by the city's No 3, No 5 and No 9 middle schools. The stop "Hongshan Reservoir", where the accident happened, is a stop located in the middle of the route.

The rescue is ongoing and investigations into the cause of the accident are underway, Beijing Youth Daily said.