A 13-year-old girl has stabbed another female student in the neck with a pair of scissors at a Christchurch high school.

Hornby High School has suspended the girl for the stabbing, which happened at the end of the morning break.

Principal Richard Edmundson said the Year 9 student stabbed a classmate with a pair of scissors she usually kept in her pencil case. 

The victim, another 13-year-old girl, was not seriously injured and declined to go home after being stabbed.

"It is a stabbing, but in the sense it required a plaster and the girl didn't want to go home."

The victim saw the school nurse, but did not require further treatment and remained at school for the rest of the day. 

Her attacker had been suspended, Edmundson said.

The school's board of trustees would decide whether she could come back to school later, or whether she should be excluded permanently.

Such an incident was "highly unusual" at Hornby High School, and it was lucky no one was seriously hurt, he said.

"Let's thank our lucky stars that no lasting physical harm was caused, because it could have been [much worse], hence our suspension.

 - The Press