A school principal has been stabbed at a secondary school in Melbourne’s southeast, triggering an emergency response and a campus-wide lockdown.

Emergency services were called to the Acacia campus of Keysborough Secondary College at about 3pm on Tuesday after reports of an assault.

The principal was taken to hospital with injuries that are not considered life-threatening.

The alleged attacker has been taken into custody.

Police confirmed the two men are known to each other and will be interviewed.

There are unconfirmed reports that another staff member may have been involved, though this has not been verified by authorities.

The school was placed into lockdown as a precaution while police and paramedics responded.

According to 7NEWS, some students were directed to shelter under desks during the incident.

“The principal of Keysborough Secondary College was allegedly harmed by an adult at the Acacia campus today,” the Department of Education said in a statement.

“No students or children were involved. We are grateful to staff at Keysborough Secondary College who acted quickly to contact emergency services during this distressing incident.”

Helicopter footage from the scene showed multiple police and ambulance vehicles at the school, and a man being placed on a stretcher and loaded into an ambulance.

Images: 7NEWS