The blaze in Nyeri County’s Hillside Endarasha Academy broke out at around midnight, police said, engulfing a dormitory where the children were sleeping.
“There are 17 fatalities from this incident and there are also others who were taken to hospital with serious injuries,” said national police spokesperson Resila Onyango.
Police did not release the ages of the victims.
“The bodies recovered at the scene were burnt beyond recognition,” she said.
Several others were injured, Onyango said, 16 of them seriously, and had been rushed to a nearby hospital.
“More bodies are likely to be recovered once (the) scene is fully processed,” she said.
The cause of the fire remains unknown, she said, but an investigation had been launched.