Fire incidents were on Sunday night reported at two schools.
Kenya Red Cross said on twitter that the affected schools are St. Barbara Kanga'aru Secondary School in Kagio, Kirinyaga County, and Friends School Kamusinga in Bungoma County.
The emergency response agency said it deployed its teams to the scene.
The fires were reported hours after Highway Secondary school in Nairobi was closed indefinitely following a fire at one of its dormitories.
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Bungoma county fire brigade crew puts out fire at Kamusinga school's Jamuhuri dormitory. /BRIAN OJAMAA
Red Cross said 12 casualties were rushed to Kenyatta National Hospital for smoke inhalation and soft tissue injuries.
The fire is suspected to have been started by a student. Five students were arrested and are helping with investigations.
The incidents brings to over 50 the number of schools that have experienced arson cases across the country.
Bungoma county fire brigade crew puts out fire at Kamusinga school's Jamuhuri dormitory. /BRIAN OJAMAA
In Mt Elgon, police are investigating a fire incident at Kapsokwony Boys High School in which a dormitory was razed down.
Principal Joab Otieno said no student was injured in the Friday night fire.
A similar incident happened in 2016.
The fire started when students were asleep but they all escaped.
Students, teachers and neighbours watched as property went up in flames after failed efforts to put out the fire.
Board of Management deputy chairman Justus Omukule
said the school might be forced to close.
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