A stunned principal at a Canterbury school says she felt sick when a teen student sparked an international police drama by threatening to shoot everyone at his school.
The Year 9 student at Rangiora High left a note on his fake Facebook profile on Thursday, initiating a frantic response from police in Texas, US.
A mum in North Carolina alerted US authorities after her stepson saw the threat on the internet.
The boy wrote about being bullied, claimed he was burning inside with violence and said: "I shell (sic) go to school and shoot everyone in sight".
Police took the threat seriously as the message said the boy lived in "Mt Heaven, Texas" - similar to the town of Mt Haven in the same state.
Texas police tracked the boy through his internet provider to the 1800-pupil school in North Canterbury and emailed Rangiora High principal Peggy Burrows.
"I was shocked when I checked my emails about 8.15am on Friday and there was a message from a police investigator in Texas explaining they had identified a threat from a boy at our school who had been saying he wanted to shoot everyone," Burrows told the Herald on Sunday.
"I felt absolutely sick because a lot of boys in our area have gun licences, go pig-hunting and stag-stalking, and are very savvy huntsmen, so I took this very seriously indeed ... imagine if the whole thing turned into a horror like the Columbine school tragedy in America."
Burrows alerted Rangiora police and called the boy's father to the school.
The boy confessed to posting the message as a joke in response to being bullied.
"He couldn't believe what he had started and he was sitting in my office along with his dad, two police officers and a guidance counsellor," Burrows said.
"He was almost beside himself with embarrassment and said he had posted the note in response to having had a bad day at school where he felt he had been bullied by another student."
Burrows said the matter had been resolved. "No further action will be taken against the student who is receiving help."
She said the matter would be raised at assembly to emphasise to students that they were not invisible on the internet and what they could do if they felt they were being bullied.