Four Victorian primary school students, aged just six, have been suspended for attacking an older boy.
The grade-four student was set upon by the prep students at Heidelberg Primary School, in northeast suburban Melbourne, on Wednesday.
The 10-year-old was taken to hospital but has since returned to school.
In a written statement on Friday, school principal Janet Ringrose confirmed the incident had occurred, saying the four students had been suspended.
"This behaviour is out of character for our students and our school," Ms Ringrose said in the statement.
"As soon as we became aware of the matter, we contacted the relevant authorities, organised immediate medical attention and the respective parents were promptly notified.
"We have been in constant touch with the boy's family to offer our support. The boy is now back at school.
"Further steps have been taken to ensure all students are clear that this behaviour is unacceptable.
"I am confident that the boys understand it was absolutely the wrong thing to do."
An Ambulance Victoria spokeswoman said paramedics were called to a report of an assault at the school just after 2pm (AEDT) on Wednesday and arrived to find the 10-year-old being cared for by staff.
"There were no obvious injuries but we transported the patient to the Austin hospital as a precaution," the spokeswoman added.
Victorian Premier John Brumby said the incident would shock many Victorians and a full report would be prepared by the school.
"It's the type of incident that you don't think could occur or would occur," Mr Brumby said.
"It's completely unacceptable behaviour." Mr Brumby said tackling violence in schools and on the streets came down to respect.
"If you respect other people, if you respect your classmates, you don't go around hitting them at school, it doesn't matter whether they're prep kids, it doesn't matter whether they're older kids.
"We need to get on top of this issue. It's thankfully, I think, a very isolated issue, the bulk of our schools are very good ... and you don't see this sort of incident."
