A 13-year-old boy had to be treated in hospital for a puncture wound to his stomach after a stabbing at a top grammar school.
A fellow pupil at St Columb's College in Londonderry was arrested in connection with the attack but was later released.
The incident is believed to have happened last Friday but details only came to light this morning.
It is thought that a row broke out within the art and science |department and that a 12-year-old picked up an instrument and stabbed his classmate.
The wound was thought to have required a single staple at |Altnagelvin A&E department.
The 13-year-old victim is now recovering at home.
Foyle MLA and former pupil at the school, Mark H Durkan, said he was confident that a thorough |investigation would be conducted by the school. He added: “I think it is important at this stage not to jump to conclusions and assume this was a premeditated attack where a weapon was taken into school.
“I have every confidence that Sean McGinty, the principal of St Columb's, will conduct a thorough investigation and I know from when I was a student in the school and he was one of my teachers that this is a most unusual occurrence.
“The school does not have a problem with discipline and I know the parents who send their sons to the college do so with confidence in the excellent pastoral care the school offers.”
A spokeswoman for the PSNI said they are investigating a report of a stabbing at a school which was reported to them at 6.09pm on Friday.
She added: “A 13-year-old boy sustained an injury to his stomach which required medical treatment.
“A 12-year-old boy was arrested and later released pending report to the Public Prosecution Service.”
No one from St Columb's College or the Western Education Board was available for comment.
Founded in 1879, St Columb's College is Derry's oldest and largest Catholic Boys grammar school. It has a tradition of scholarship and the unique distinction in Ireland of being the alma mater of two Nobel Laureates, John Hume and Seamus Heaney.
The school has over 1,500 students and is a Specialist School for mathematics and computing, and the quality of its work in information communications and technology has been recognised by the achievement of the BECTA ICT Charter Mark and of a National Training Award for staff development in the subject.
In January 2008 the College received further recognition as an exemplar of Best Practice in the Public Sector while in November 2008 St Columb's won joint Best Whole School Award in Northern Ireland at the ICT Excellence Awards.