He added that the police have already launched an investigation to establish the cause of the fire.
"We cannot, at this moment, say what caused the fire. Our officers are here, and they are investigating what actually caused the fire," he added.
His sentiments were echoed by the Nyanza region education director, Nelson Sifuna, who noted that the incident has directly affected at least 260 students at the school.
According to Sifuna, the fire started at a store in the school where mattresses are kept before spreading to a nearby dormitory.
The fire incident happened a few hours after Kisumu Girls, which shares a fence with Kisumu Boys, was closed indefinitely following a student's unrest.
It is unclear whether the two incidents are related, but security officials told Standard Digital they were not ruling out an arson attack.