Seventeen people are recuperating at Molo Sub-County Hospital after they injured in a road crash at Migaa along the Nakuru-Eldoret highway.
The Wednesday morning incident involved a lorry and bus which were both heading to Nakuru.
According to the hospital's superintended Dr Bernard Warui, the victims were brought in by Kenya Red Cross officials at about 8.30am.
"Most of them sustained minor injuries and they are all in a stable condition. Nurses have taken them through various tests and treated them accordingly. No referral has been made so far," said Dr Warui.
Two more people who sustained serious injuries were rushed to Nakuru Level Five Hospital where they have been admitted.
According to a volunteer with the Kenya Red Cross, 15 others people who were slightly injured were treated at the scene.
Nakuru County Police Commander Stephen Matu said the 63-seater bus belonging to Tosha Express was hit from behind by a speeding lorry making it to roll into a ditch.
The lorry, which appeared to have experienced brake failure, sped off even as police tried to stop it.
"The speed at which that lorry was travelling was not normal at all. The driver was totally out of control and could not be stopped whatsoever," Mr Matu said.
Witnesses say the lorry was heard hooting loudly and vehicles that were in front of it could been seen giving way for it to pass.
"The bus was travelling at an average speed and as the driver tried to give way to the speeding lorry, it was smashed from behind forcing it to fall into a trench," said John Mwamba, a witness.
Mr Matu said police are investigating the matter and that a manhunt has been launched for the driver of the lorry.
"Brakes failure can be troubling especially on a busy highway. But it was rude for the driver to speed off after knowing that he had caused an accident that involved lives of innocent people. What if deaths occurred?" Mr Matu asked.
He said it would have been respectful of the driver to find a way of stopping the lorry or directing it to a nearby police station.