The injured include two 16-year-old female students and a 48-year-old female teacher. They were admitted to the Diyatalawa Base Hospital and the Badulla Teaching Hospital for treatment.
According to initial investigations, the accident occurred while the students were conducting a science experiment during a laboratory lesson. Police said a beaker containing a substance used for the experiment had exploded while it was being heated, causing injuries to those nearby.
Police said further investigations are being carried out into the incident.
