Five people died on Thursday morning when a 14-seater matatu rolled and landed in a ditch at Kipsoen area on the Bomet-Kisii highway.
One passenger died on the spot while four others succumbed to their injuries while undergoing treatment at Longisa County Referral Hospital.
Fourteen other passengers are undergoing treatment following injuries sustained in the early morning crash.
"Four men and a woman died following an accident at Kipsoen area involving a Kisii-bound matatu belonging to Egesa Sacco," said Bomet Sub-County Police Commander Musa Omari.
Mr Omari said the injured were rushed to Longisa County Referral Hospital, while two others, who were in critical condition, were transferred to Tenwek Mission Hospital.
He said the driver of the matatu, which was travelling from Nairobi to Kisii, lost control of the vehicle and landed in a ditch as he tried to avoid hitting an oncoming car after overtaking another vehicle.
Some of the passengers were thrown out of the vehicle while others were trapped inside.
Members of the public and motorists pulled the victims out of the wreckage before rushing them to hospital.