The armed offenders squad was sent to a Dunedin High School this morning after it received a call from someone saying they had a bomb.
The receptionist at Logan Park High School, in North Dunedin, received the call just after 11am.
Deputy principal Peter Hills said the call was from a male, who said he had a bomb and detonator.
The caller gave no indication of where the alleged bomb was, or the intentions.
Mr Hills said the police were called, and the armed offenders squad carried out a sweep of the school, and were satisfied there was no immediate threat.
Mr Hills said the police had now traced the call, which came from a landline, and they have visited the address.
Peter Hills said it appears the call was a prank, but it created a lot of anxiety, especially for the receptionist who took the call.
As it was a teachers only day there were no students on site, but there were teachers and contractors.
Mr Hills said hoped the incident would have serious repercussions for the caller.
"No one should receive that type of call, especially not in 2016."
He said the school did not know who the caller was, but were not assuming it was one of their students.