According to police, the accident occurred when a minibus rammed into a stationary truck at Kiambaa.
“We lost nine people in the accident,” Traffic Commandant Samuel Kimaru said.
The accident comes two days after nine people perished in another accident involving a bus and a van at Pinying area of the Ntulele black spot near Narok.
Two months ago, 41 other people were killed at the same black spot when their bus lost control and rolled several times, leaving more than 20 others wounded.
In an effort to curb the increasing menace Transport Cabinet Secretary Michael Kamau announced tough penalties for PSV owners whose vehicles are involved in accidents.
Police statistics show that up to 3000 people have been killed in road accidents since January this year.