Police in Gilgil, Nakuru County are looking for a student at Shiners Boys High School, who allegedly stabbed to death his classmate on Saturday night.
This followed an altercation between students, police and other students said.
Four candidates are reported to have differed over personal items destroyed in school, leading to the incident that happened at about 8 pm.
The victim was declared dead on arrival at Nakuru Level Six Hospital, where he was rushed for treatment.
Gilgil sub-county police commander Winstone Mwakio said the suspects had earlier on been suspended from the institution but reported back for exams and found their personal items destroyed and suspected the victim could be responsible for the acts.
He wondered how the killer knife was sneaked into school even as he expressed concerns over indiscipline as the main cause of the incident.
Mwakio revealed that the main suspect fled away with the knife and is being pursued since his three accomplices have been identified and detained.
The victim was pronounced dead on arrival at Nakuru Referral hospital.
The body was taken to Nakuru morgue pending an autopsy examination.