Students were left stunned when a teenage boy walked into their classroom and allegedly stabbed a teacher and two students during morning roll-call at Bonnyrigg High School before walking away without saying a word, a witness says.
A 16-year-old male student has been arrested in the car park of a nearby supermarket over the stabbing at the school on Elizabeth Drive in Bonnyrigg on Thursday morning.
A meat cleaver, a knife and a pair of scissors could be seen in the gutter not far from where the boy was arrested.
"I didn't kill anyone. You have to tell my brother," the 16-year-old boy, who was wearing handcuffs and a school uniform, said.
Police and paramedics were called to the high school about 8.45am to reports that a number of people had been stabbed in the school's science block. A witness initially said a metal ruler had been used in the stabbing, but police later said they had seized two knives at the scene.
A 48-year-old science teacher was stabbed in the upper back, while two students - a 16-year-old boy and a 15-year-old girl - were stabbed in the shoulder. The injured teenagers are Year 11 students at the school, police said.
A Year 11 student, who declined to be named, said she was sitting in roll-call in the school's science block when a boy walked in and stabbed the trio.
"He just walked in and stabbed them, then walked out," she said.
She said the boy was supposed to be in roll-call that morning. He didn't say anything and most of the students sat in shock before they realised what had happened.
Another student said the school went into lock-down.
"The teacher didn't deserve to get stabbed," he said.
Year 10 student, Isaac, said the teacher, who he named as Miss Cox, was popular with students.
"She's well liked," he said.
All of the patients were in a stable condition in hospital, and their injuries were not life-threatening, police said.
A large number of police swarmed the school and the neighbouring shopping complex. They arrested the 16-year-old male student in the car park of the Aldi supermarket, about 100 metres away from the school.
An Adidas bag remains in the gutter, with a knife, a meat cleaver, a pair of scissors and an empty water bottle visible.
The boy was taken to Fairfield Police Station, where he was being questioned over the stabbings.
The students have been assembled in an outdoor area at the school, however some parents have already come to collect their children.