According to police, all the deceased were residents of Dabgarwad area of Ahmedabad and came to the Galteshwar temple, situated on the banks of Mahi river.
The deceased have been identified as Triloknath Prajapati had come to the temple along with his family.
After visiting the temple this afternoon, Triloknath's wife Badamidevi (40), son Rajesh (19), daugther Sonia (16) and their neighbour's son Vikas Hemraj (16) went to the river to take a holy dip. Triloknath did not accompany them.
Fire brigade officials later fished out the bodies of the victims from the river.
Triloknath, who went into a state of shock due to the tragedy, was rushed to hospital as he complained of chest pain, police said.