A police spokesperson said enquiries are under way after several phone threats were aimed at schools in Kaikoura, Rolleston, Geraldine, and Ashburton.
Threats were also reported at schools in Marlborough, Masterton, Greymouth, Queenstown, Levin, Whanganui, Takaka, Dunstan and Palmerston North.
Rolleston College was among the schools targeted. The Rolleston campus was locked down earlier this afternoon and police were present, but students have returned to class.
Meanwhile this afternoon, Marlborough Girls' College in Blenheim was also locked down and other schools in the area voluntarily locked down.
The public were asked to avoid the area.
The threat was not believed to be linked to threats toward other schools made this week, police said.
Awatapu College in Palmerston North also received a bomb threat earlier today, according to a post on the school's Facebook page.
"Police take threats of this nature extremely seriously and is making enquiries to determine the source of the calls," the spokesperson said.
"At this stage Police do not believe there is a safety risk."
Police have also responded to threats at Wakatipu High School in Queenstown, Dunstan High School in Alexandra and Waitaki Girls' High School in Oamaru.
Emergency services, including Fire and Emergency New Zealand, attended a callout at Wakatipu High School and students were evacuated.
Horowhenua College also confirmed it had received a bomb threat, RNZ reported.
Greymouth High School received a phone threat too.
"We have worked with the police and they have been into school. Police do not believe that there is a safety risk," a spokesperson said.
In Kaikōura, three primary schools told RNZ they had not received threats, while Kaikōura High School did not wish to comment.
Several West Coast schools also said they had not received threats, including John Paul II High School, Blaketown School, Cobden School and Greymouth Main School.
'Schools across the motu'
Ministry of Education hautū (leader) of operations Sean Teddy said the ministry was "aware that multiple schools across the motu have received a threat".
"All schools and kura have established emergency management protocols in place, which they activate if a risk is identified.
"We are in contact with those schools and kura that received the message to provide guidance, if needed."
Two days ago six North Island schools were either thrust into lockdown or evacuated following threats made towards the schools over the phone.
The Ministry of Education said it was aware of threats made towards five schools in Waikato and one school in Gisborne.
Matamata College, Matamata Intermediate, Thames High School, Cambridge High School, Firth Primary School and Lytton High School all announced on Facebook around noon that they had received threats and were either evacuating students, or had gone into lockdown.
At the time ministry hautū for the Central Region Jocelyn Mikaere said the schools immediately initiated their emergency management plans and the police responded.
"Our teams are in contact with all of the schools and are prepared to provide whatever support is needed," Mikaere said on Tuesday.
A police spokesperson said officers investigated the inquiries and believed there was no specific safety risk.
"Investigations into the source of the threats are ongoing.
"Police extends thanks to the schools involved for following their emergency procedures, and to the wider school communities for their co-operation."
On Wednesday an anonymous threat was also made to Marlborough Girls College - police attended and were speaking with one person.
-RNZ, NZ Herald, Star News, ODT
