The driver of the ill-fated bus carrying 60 passengers to a "satsang" from Khurja to Aliganj in Etah district lost control at a sharp turn and overturned, they said.
Though the capacity of the bus was around 30, it was packed with 60 people, police said, adding, that the injured have been admitted to Jawaharlal Nehru medical college and district hospital where the condition of five of them was stated to be serious.
The bodies were being sent for post mortem examination, police added.