Police said no injuries were reported following the fire that started at a kiosk and spread to others. The fire brigade put it out.
Fire cases have been on the rise in Kibera and other slums in the city.
In the area in 2015, five siblings were burnt to death in a fire that razed their house and about 100 others.
Police said they were sleeping when the fire started at one of the other houses at around 10pm.