Teachers at Calwell High were forced to lock the school gates and call for police help during a week of violent episodes involving gangs of armed youths and students.
Education Minister Andrew Barr has confirmed police are investigating the violence.
Last Thursday, a 16-year-old Calwell High student, who cannot be named for legal reasons, was walking home from school when he was allegedly attacked by a gang of six older youths.
According to a witness, the youth was knocked to the ground and "jumped on and repeatedly kicked in his head". He was taken to Canberra Hospital with skull and facial injuries.
The next day, about 1pm, teachers locked the gates and ordered students not to leave as two carloads of youths wielding baseball bats circled the school.
The youths yelled threats and made phone calls to students threatening violence.
Police were called and several students were interviewed.
Concerned parents rang The Canberra Times to say they feared for students' safety and to demand reassurances from school authorities and ACT police that they were addressing the problem.
Mr Barr told The Canberra Times he had asked his department to work closely with the troubled school to formulate a strategy to combat the outbreaks of violence.
The alleged assault of the 16-year-old follows a incident just four days previously when three males entered a Calwell High classroom and allegedly assaulted a male student. The attackers told the class teacher the intended victim was wanted at the front office, but when asked, could not produce a note as proof.
The student was repeatedly punched about the face until two female teachers intervened.
The victim and the attackers were separated by the teachers and police were called. The student was taken to Tuggeranong Police Station with his parents and made a statement. He was then taken to hospital for treatment.
A student of Calwell High filmed Thursday's assault on a mobile phone and showed the footage to several students before he was allegedly told by a teacher to delete it.
The Canberra Times spoke to several students and parents, who agreed only to do so on condition of anonymity.
"These are not isolated incidents," one parent said.
"There are gangs of armed young men, who deliberately are aggressive and intimidating, not to mention violent, towards certain members of the school.
"They come to the school looking to cause trouble and the teachers are powerless to stop them as they are in large numbers and more often than not carrying weapons.
"It is outrageous this can happen at a school where we send our children to be safe. The police and the school need to address the community with their strategy to stop violent attacks on children."
Mr Barr said yesterday he was aware of each incident and the department was in close consultation with the school.
"The incidents that occurred last week are currently under police investigation so I am unable to comment on the individual cases.
"However, I do understand parents' and students' concern. I can assure them that the Government and the school believe a safe and secure environment for students is paramount. Based on information from the Department of Education and the school, I am satisfied that the school followed procedures and took all necessary steps on Friday to secure student safety. The school and the Department are continuing to work with police," he said.