Police said the two cars were moving in the same direction when the accident happened near Carnivore restaurant today.
"One of the cars was carrying eight passengers and the driver lost its control before he hit the other car and rolled into a ditch," police said.
The bodies were transported to Nairobi's Chiromo Mortuary for identification.
Separately, two people were also killed in Kayole and another killed along Eastern by-pass in Nairobi on Thursday.
This comes after 11 people were killed and seven injured in an accident involving a matatu on Katito-Kendu Bay road in Kisumu county on January 6.
Nyanza traffic boss Andrew Naibei said the 11 died at the scene of the crash.
On December 10, 40 people died after a petrol tanker exploded in Naivasha county.