While bodies of 21 people were fished out from the canal, 23 others were saved by the locals and a police team.
Among those killed included 11 of a family, including a newly-wed bride, going to Ghaziabad from Aliganj after the marriage ceremony.
The injured have been admitted to a hospital, where their condition was stated to be stable, police said.
According to the passengers, the driver of the bus was in an inebriated condition.
Some passengers are said to be missing and police was trying to trace them. Their exact number is yet to be ascertained, Etah District Magistrate Lokesh M said, adding relief and rescue operation were on.
Those killed included 10 men, four women and seven children, SSP Radheymohan Bhardwaj said.