A packed bus has fallen from a bridge into a river in northern Nigeria killing 56 passengers, officials say.
The crash took place at Tanburwa bridge about 20km (12.5 miles) south of the city of Kano.
Five survivors are being treated in hospital, said Ibrahim Ahmed Ibrahim, from the federal road safety authority.
The bus was travelling from the commercial city of Lagos 1,100km (684 miles) away and the driver - who died - "may have dozed off", said Mr Ibrahim.
The bus plunged into the Gadar Tamburawa river in the early hours of the morning. Its destination the city of Maiduguri, capital of north-eastern Borno State.
An eyewitness told AFP news agency he had seen the driver with his neck stuck out of the window.
"At first, I thought he was trying to examine the front wheel of the bus. But soon after, the bus veered off the bridge and plunged into the river," the man said.
Commuters regard Lagos buses as death traps
"We have taken 56 bodies to the Murtala Mohammed specialist hospital mortuary in Kano and five are on admission in the same hospital," Mr Ibrahim said.
"I understand the driver may have dozed off out of fatigue and plunged into the river," he said.
Correspondents say Nigeria's commercial bus drivers are notorious for reckless driving.
In Lagos, the regular involvement of the buses in accidents has made commuters label the yellow buses "morgues" and the minibuses "flying coffins".
Speeding, overloading and poorly maintained vehicles are blamed by the authorities for the frequent accidents.