A school and three classrooms have been torched in the Limpopo village of Mukhomi, near Malamulele.
Police said they received a report from residents at about 02:30 on Sunday alerting them to the blaze.
“Police received information in the early hours of this morning and, on arrival, three classrooms and a staff room were on fire,” said Brigadier Motlafela Mojapelo.
Mojapelo said firefighters were called and the fire was extinguished.
Meanwhile, fire investigators from the forensic division in Pretoria were expected to visit the scene to assist in the investigation.
In June last year, mid-year examinations were interrupted after fire destroyed exam papers, other school records and school properties.
Five administration offices and three storerooms that contained five laptops, a computer, and sports kit donated by the Lotto fund, all worth about R180 000, were destroyed.