Police are investigating after 27 schools around the country received threatening phone calls this morning.
Yesterday six schools got phone calls warning of a bomb threat.
Kerikeri High School, with around 1550 students, was one of those which received a call today.
Deputy principal Daniel Wise says students have returned to class after initially being evacuated.
"Shortly before midday we received a phone call which sounded like a robotic recording saying that there was a bomb threat to the school," he says.
Mr Wise says the receptionist handed the phone to him, and he handled the call. He said the voice sounded computer-generated.
"From there we informed the police and made the decision to evacuate our students to the field.
"The police arrived shortly after that, and after a short amount of time they did give us the all clear, so all our students are back in class."
"We have provided a script to all our teachers to explain to the students clearly what had happened and that we had the all clear from the police as well as advising our community through our various alert systems," he says.
Police are attending each school and working with school management teams.
Western Heights High School in Rotorua is also in lockdown and nobody was allowed in or out of the school.
Police were at the school this afternoon.
The priority is to ensure the safety of staff and students, police say.
Yesterday, police said their initial investigation into the threats at the first six schools showed the call could have originated overseas and New Zealand could have been the latest victim in a string of international hoaxes.
Similar incidents have occurred in the US and more recently Australia, police say.
Until police can rule out any actual threat, the calls must be taken seriously.
Police say so far they have not established any actual threat to any school.
Newshub.
