A passenger bus fell off a bridge into the Ganges near Patna early on Saturday. The fate of its over 50 passengers was not known.
The private bus was on its way to Patna from Hajipur in Vaishali district when it crashed into the river after hitting the railing of the Mahatma Gandhi bridge.
"The driver lost control due to thick fog," said a police official.
Rescue and relief operations had not started even hours after the accident, and local divers refused to jump into the river to save the trapped passengers.