New Zealand could be the latest victim of a string of hoax bomb calls around the world, after six schools received bomb threats today.
Police were called to the schools -- Logan Park High School in Dunedin, Wellington High School in Wellington, Tamatea High School in Napier, Burnside High School in Christchurch, Central Normal School in Palmerston North and Brookfield School in Tauranga -- after each received very similar calls.
Local police worked with each school on a plan and a number of schools, including Brookfield, were evacuated.
National manager of response and operations Superintendent Chris Scahill says each call said an "explosive device" had been left on the school site.
Around 3:30pm, police said they were satisfied there was no risk to any school and no devices were found.
Initial investigations showed the source of the threats indicated they "may well be from overseas" and possibly made using the internet.
"We are aware of similar incidents occurring in countries around the world -- US, UK and Australia -- and these have involved recorded voice messages being directed towards schools in these countries as has happened here."
New Zealand police are liaising with other law enforcement agencies around the world in their investigation.
An initial trace of the call suggested it came from overseas, but Supt Scahill says tracking the source "can prove to be a challenge".
In a letter sent to parents of Logan Park High School students, it says a call was received at lunchtime and was reported to police.
"We take any threat to safety of the students and staff seriously and we evacuated the school, but were given the all clear by police shortly after the call," the letter reads.
They say have "well-established procedures" for dealing with such incidents and the priority is to ensure the safety of students and staff.
Supt Scahill said he was "proud" of the way the schools involved reacted to the threats.