New Zealand students could use foreign hackers to make hoax calls to schools to get out of class, a computer forensic expert warns.
Six New Zealand schools received threatening automated messages on Wednesday, and another 27 incidents yesterday triggered some lockdowns and evacuations.
Special Tactics managing director Daniel Ayers said the people behind the string of hoax calls to schools around the world were probably a group of hackers known as the Evacuators, who claimed to be Russian.
He said this group asked people to nominate schools to receive the calls.
"They have posted a message on the internet, saying that they will be offering this disruption as a service you can pay for and order for schools and rest homes and sporting functions and conferences, from the next couple of days on."
Last month a Twitter account - Evacuators 2K16 - claimed responsibility for hoax calls that closed dozens of British and French schools.
The account - which was soon closed down - used a profile picture of Vladimir Putin and an email with a Russian ".ru" suffix. The group has continued to operate using online messaging and email, reported the Independent.
Mr Ayers said the hoaxers were using voiceover IP software that allows people to use the internet to make voice calls.
"It could be called identity laundering in the sense that it's like money laundering, where people flow money through a whole lot of different places and disguise where it came from. And here, telephone calls are going through the internet to make them look like they come from new Zealand, when in fact they don't."
Police said no actual threat had been established.