Relieving principal Ben Higginbottom wrote to staff on Wednesday morning to inform them of the incident, which he said occurred in the support unit play area on Tuesday.

"A student, in the process of attempting to harm another student, inadvertently harmed two staff members," Mr Higginbottom wrote.

"Both staff received medical treatment.

"No students were physically harmed.

"I must acknowledge the outstanding work of those two staff members, other members in the immediate vicinity, and other staff that assisted in resolving the matter and providing post incident care.

"Your care and cooperation of all involved was simply remarkable under such circumstances."

Mr Higginbottom held a "debrief" for staff on Wednesday afternoon and reminded them of their access to the Department of Education's Employee Assistance Program, "including post incident support".

A department spokesperson told the Newcastle Herald it was "not appropriate to detail the personal information of staff or students".

"An incident occurred and appropriate disciplinary action has been taken along with support offered to affected staff," they said.

Schools are required to contact the department's Incident Report and Support Hotline - which is staffed by NSW Police officers - relating to activities such as violence; misuse of substances; weapons; welfare; emergency situations; and malicious use of technology if there is a concern for the student's safety.

A NSW Ambulance spokesperson said it appeared paramedics did not attend the school.