A 17-year-old pupil was stabbed to death at Leiden Secondary school in Delft on Monday morning, Western Cape police said.

The boy was found with a stab wound to his chest, and he died due to his injuries, police spokesperson Sergeant Noloyiso Rwexana said.

Rwexana said a fight had allegedly broken out between pupils at the school.

Three pupils, aged between 16 and 18, were arrested. Police were investigating a case of murder.

Jessica Shelver, spokesperson for Western Cape education MEC Debbie Schafer, said the stabbing was allegedly gang-related.

Rwexana said they would continue to monitor the school.

Anyone with more information about the incident was asked to contact the investigating officer Warrant Officer Adolf Petersen on 071 8916513 or Crime Stop on 08600 10111.