At least 12 people have been confirmed dead and two others seriously injured in a road crash at Salgaa, on the Nakuru-Eldoret highway.
The Sunday morning incident that occurred at around 3am involved a Great Rift Shuttle and a Mercedes-Benz Actros.
"All the 11 passengers and the driver of the shuttle died on the spot," Mr Kioko told Nation.
Rongai OCPD Japheth Kioko said the accident happened after the matatu driver lost control after hitting a cow, before colliding with the truck.
The truck driver and his turn boy suffered serious injuries and were taken to Nakuru Level Five Hospital.
The bodies have been taken to the county's mortuary.