A violent scene erupted at a Sydney high school leaving a teacher and two students being treated for stab wounds.
Before classes even started paramedics and police were called to Bonnyrigg High School after three people were injured.
Police arrested a 16-year-old male student in the car park after emergency services were called to the school on reports of a stabbing occurring.
The boy had three knives on him, according to police.
The 48-year-old female teacher was stabbed in the back apparently while opening the classroom for the day.
A 15-year-old girl is reported to have been stabbed from behind in the shoulder, and a 16-year-old boy was stabbed in the chest.
Investigations are ongoing, with the arrested 16-year-old being held in custody.