The driver was also injured in the incident, superintendent of police PC Harsha told a news agency.
The wounded people have been taken to government hospital in Sira.
The mishap took place when the driver was trying to park near a Dhaba. He reportedly lost control leading to the bus toppling.
In other incident, three people were killed on the spot two in hospital when a iron-ore laden lorry and Tata Ace (SUV) collided on Sunday, Dec 27 night, the police informed.
13 were injured in this incident which took place in Gadag, located in north Karnataka.