A baseball bat-wielding teenager attacked a female lecturer before three brave students tackled him to the ground at the Australian National University in Canberra.
The 18-year-old man, who is also a student, entered a classroom near the Copland Lecture Theatre at about 9.15am on Friday and allegedly assaulted a number of people.
He was tackled by other students, who were left with broken bones, before being detained by police who attended. Emergency services remain on the scene.
A female student who was in the classroom at the time described the terrifying moment the the man suddenly stood up and started to destroy everything in his path before attacking others.