A 15-year-old girl has been arrested for allegedly stabbing a fellow school pupil on Tuesday at a high school in Isipingo, south of Durban, police say.Provincial police spokesperson Brigadier Jay Naicker said the stabbing took place at 10:00. According to Naicker, the girls were involved in an argument moments before the stabbing.The victim - also 15 - was taken to hospital for treatment, Naicker said.A case of assault with intent to cause grievous bodily harm is being investigated by Isipingo police following the incident. ALSO READ: Mossel Bay teen bludgeoned to death for her branded shoesThis is the third reported school stabbing in as many days.Khuselo Ndanda, 16, was stabbed to death at Hillcrest Secondary School in Mossel Bay during breaktime on Monday, allegedly by three of his classmates. Police said he sustained multiple knife wounds to his upper body.Three suspects have been arrested. They are understood to be in Grades 10-12.In Gauteng, a 14-year-old pupil at Thuto-Tiro Comprehensive School in Sebokeng was stabbed to death by a fellow school pupil.At the time, Gauteng education department spokesperson Steve Mabona said a pair of scissors was used to stab the pupil.A 15-year-old has since been arrested for the murder.