The mishap occurred after the driver lost control of the vehicle while trying to negotiate a sharp curve, they said.
Police said about 40 persons were said to be travelling in the private bus and most of them have been rescued.
Rescue operations are still on to trace any person trapped in the vehicle which plunged into the Sulekere Lake. A crane has also been sought for assistance, they said.
The injured have been shifted to nearby hospitals and most of them have suffered minor injuries, they added.
