According to police, the number of casualties is likely to rise.
"Twenty bodies have been taken out from the river after the bus fell off a bridge into Purna river near Supa village," Superintendent of Police, Navsari, M S Bharada told PTI.
Navsari is located 285 kms away from here.
"The bus was going from Navsari to Ukai when the accident took place. We do not know the exact number of people travelling in the bus, but it is said that it was full (to capacity)," the officer said.
"Casualties can rise," Bharada said, adding the injured passengers were rushed to various hospitals in Navsari.