Video footage shows the bus was swept away after the driver tried to cross fast-flowing water over a bridge in the Enziu River, about 200km (125 miles) east of the Kenyan capital, Nairobi.
The bus had been hired to carry church choir members to the wedding.
Four of the dead were children and a least 12 people have been rescued, local media reports say.
However, it is unclear how many people were in the bus at the time though some Church leaders are saying that they were 50 passangers in the bus.
It’s said that the driver was not familiar with the route and the bridge over the river in Mwingi, Kitui county, hence that led to that bad accident
The Kitui Governor mama Charity Ngilu said the “terrible” accident happened on Saturday morning.
Unusual heavy rains have been falling in many parts of Kenya recently, including in some drought-hit regions where domestic and wild animals have died because of lack of pasture.
