Three children were seriously injured after a bus they were travelling in overturned near Capital Centre on Mombasa road.
At least 13 other casualties have been reported from the Wednesday morning incident, and seven are said to be in critical condition.
They were rushed to the Kenyatta National Hospital by the Kenya Red Cross.
The driver of the bus is said to have been speeding, after which he lost control of the vehicle.
Police arrested the driver who will be charged with reckless driving.
The bus is said to belong to Trinity Transporters.
In another Wednesday morning accident, two people died after a bus they were travelling in rammed into a trailer on the Nairobi-Naivasha highway.
At least 26 others were injured in the 1.30am incident in Kaimbaa area, while the trailer also rammed into another trailer.
Police said all the vehicles were traveling towards Nairobi.
The injured were
rushed to the Kikuyu Hospital.
