A bomb threat received by a Mount Maunganui school today was one of 13 calls made to schools around the country.
Police said in a statement made today that they responded today to "calls of a concerning nature" which began around 11.20am and stopped around midday.
Read more: Bomb threat at Mount school
Police worked with the school's management teams to decide on the appropriate response and a number of schools made the decision to evacuate, including St Thomas More Catholic School in Mount Maunganui.
The calls the schools received had similarities to the calls received by 27 schools, including Brookfield Primary School, last month.
These involved the use of a synthesised voice, with calls occurring at a similar time and day of the week.
Read more: Bomb threat at Broofield School
At least three of the schools called today had received calls previously.
Police said they were undertaking a number of lines of inquiries to establish the exact origin of these calls, and are continuing to work with the Ministry of Education and individual schools to gather information and ensure the safety of staff and students.
Similar incidents have occurred overseas in United States, and more recently Australia.
Until police can rule out any actual threat, police said they would take all such calls seriously and respond accordingly.
"How a school responds to these calls is a matter for the schools' management in conjunction with police.
"Schools will respond differently according to their individual circumstances and the information available to them," the police statement said.
Police would not disclose the names of each school who received a call today given the ongoing investigation and in the interest of preventing further such calls being made to other schools.