A Napier school was evacuated yesterday after fears a bomb had been planted on the grounds.
Tamatea High School received a phone call warning of the bomb at about 12.30pm.
Principal Robin Fabish said the school took the threat seriously.
"We immediately called police, who had someone here straight away."
Mr Fabish said he had a feeling it might have been a hoax but he wasn't taking any risks and had to make sure the 269 students were safe.
The school sounded the alarms and staff and students gathered at the mustering point.
"We briefly explained the situation and sent the students home."
The school was searched and police ascertained there was no threat.
Mr Fabish took to Facebook to inform parents there was no longer a threat.
He said he was happy with the way the students took the situation in their stride.
"They were fantastic, they responded quickly."
Any students upset by the incident would be offered counselling.
Mr Fabish said it would be business as usual at school tomorrow.
"It's been a bit of an unsettling day.
"It will be nice to return to a sense of normality."
He had no clue why his school was subject to the threat.
"I don't know why we were targeted or what's behind it."
A senior student at the school, who did not want to be named, said they were enjoying their break, sitting, eating and chatting when the alarm sounded.
"We figured someone had just pulled the alarm.
"We went to the quad and we heard some juniors talking about a bomb but thought they were full of it."
The principal then confirmed the reason for the alarm.
"We then thought, 'wow this is serious'. I did have a feeling it was false, though, so I wasn't too scared."
The student said others at the school weren't quite as calm.
"Some of them were quite frightened about what could have happened."
The student said they believed it was the right call to send everyone home.
"Safety has to come first."
The ominous call wasn't the only one received in New Zealand yesterday. Police had to deal with incidents at several schools, following calls of a "concerning nature".
The other schools were Logan Park High School in Dunedin, Wellington High School in Wellington, Burnside High School in Christchurch, Central Normal School in Palmerston North and Brookfield School in Tauranga.
Superintendent Chris Scahill last night confirmed six schools had been cleared, after each reported a call of a "concerning nature".
Local police attended each school and some schools had already made the decision to evacuate.
By 3.30pm, police were satisfied there was no risk at any school. No devices had been found.
Mr Scahill said police took such threats extremely seriously.
"Given the undue alarm they cause and the disruption to school activities, we undertake a thorough response whenever threats of these nature are received."
Police are continuing to investigate the source of the calls, although initial inquiries indicated the origin might be overseas.
Police were aware of similar incidents occurring in places such as Australia and the United States.
"These have involved recorded voice messages being directed towards schools in these countries."
Because of that, police were investigating whether yesterday's events were the latest in that string of incidents and would liaise with law enforcement agencies overseas.