Nakuru traffic commandant Mary Omari added 16 others were injured in the collision.
The accident was caused by the truck driver, who was "free wheeling," or coasting with the wheels disengaged from the drive train, Lee Kinyanjui, Kenya's National Transport and Safety Authority chairman, told Nairobi news radio station Capital FM.
The accident occurred five days after at least five people died in a collision of two buses in Keroka, Capital FM said.
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