Thirteen other people were critically injured in the Kisumu accident.
Nyanza regional traffic officer Thanju Mwangi said those injured were admitted to various hospitals within Kisumu.
Mwangi said the accident occurred when the driver of the saloon car was trying to overtake six vehicles and it rammed into the front wheel of the trailer heading to Maseno from Kisumu.
Mwangi said the vehicle which was headed to Kisumu from Maseno lost control and hit the PSV matatu which plunged into the nearby ditch.
“The driver was speeding during the accident,” he added.
The traffic boss issued a stern warning to motorists against overspeeding and carrying excess passengers.
“The drivers should be very careful on the roads, especially now that children are heading back to school. Those disobeying the traffic rules will be dealt with accordingly,” Mwangi said.
