The mishap took place when the bus, carrying 30 students, was proceeding from Moolasala village to reach the school at Peddapalli, Circle Inspector Pingili Prashanth Reddy said.
The private school bus overturned when the driver took a sharp turn in a bid to avoid collision with a Road Transport Corporation bus coming from the opposite direction, he said.
The injured students have been admitted to Peddapalli Government Hospital, he added.
A case has been registered against the school bus driver, who also fractured his hands in the accident.