Rescue operation is on going at Aponmo village near Akure in search of passengers of an 18-seater bus, which plunged into the Owena river.
The Federal Road Safety Corps (FRSC) sent in rescue team from its Ondo town Unit Command and Zebra Unit in Akure.
Eyewitnesses said driver of the bus lost control due to over speeding and plunged into the river.
It was learnt that six passengers have been rescued while four have been pulled out dead.
Witnesses said rocks at the bottom of the river might be responsible for the deaths due to impact.
Spokesman for the Ondo FRSC, Abiola Fadumo, who confirmed the accident said rescue operation was ongoing.
He promised to give updates soon.