"The school was just put into lockdown as a precaution - there was no threat to students other than the ones who were involved in the initial altercation."
All students remained in supervised study during period four and were not allowed to go outside.
The police were called and they stayed on site to patrol the area to ensure the group did not return, Whitehead said.
There were no injuries and the school's response to the incident ran pretty smoothly, he said.
"The priority of course was the students on site at the time."
A police spokesman said police attended the school after the report of an altercation and the site remained on lockdown as a precaution for a short time.
Principal Peter O'Leary declined to comment when approached by the Herald.
Opunake High School is a co-educational secondary school that was established in 1925.