The scene of the accident (Photo: Hoang Dat)
The crash occurred at about 7.40 am on National Highway 174 on the section linking National Highway 32 with Road 174, in Phinh Ho Commune.
The bus, bearing licence plate 29B-614.xx, was travelling to a branch of Hoa Mi Kindergarten in Phinh Ho when it lost control and rolled over. Eighteen people who were mostly teachers from Hanoi were on board at the time, local authorities said.
At least nine people killed in the accident (Photo: Duc Mau)
Officials said the accident happened at the foot of a long downhill slope, with preliminary findings pointing to a possible brake failure.
Several victims were trapped inside the severely damaged vehicle. Rescue teams were dispatched with specialised equipment to retrieve bodies and assist survivors.
Authorities are continuing to investigate the cause of the accident.