The incident occurred late last night when driver of the bus lost control over the vehicle and it fell into the canal, they said.
While 19 people were killed, 23 others were saved by the locals and a police team. The injured have been admitted to a hospital, where their condition was stated to be stable, police said.
The bus was going from Farukhabad to Delhi when the mishap took place.
Some passengers are said to be missing and police was trying to trace them. Their exact number could not be ascertained yet, Etah District Magistrate Lokesh M said, adding relief and rescue operation was on at the spot.