Students from a prestigious secondary school ran amok, damaging property and allegedly running through traffic with a first-year pupil in a go-kart.

The 230-year-old St Kieran's College in Kilkenny City has turned out dozens of All-Ireland senior and minor Kilkenny hurlers.

But a parents' organisation has called conduct by Leaving Cert students on their final day of school, which resulted in a pupil being injured, as "unacceptable".

The majority of 120 Leaving Cert students behaved themselves as they dressed in superhero outfits for their last day at the school, which is a long-running annual tradition.

But some went to nearby Coláiste Pobail Osraí, where several attempted to gain access to the school building.

The students were stopped as they were making their way into the school hallway, but their antics outside the building, with water guns and banging on windows, resulted in a window breaking and shattered glass landing on one of the first year Coláiste students.

It is understood that the boy who was sitting under the window was grazed as glass pieces landed on his head and clothing. The students and teacher in the room were said to be shocked.

The Kieran's College students apologised straight away to the school principal, Cathnia Ó Muircheartaigh, and later informed St Kieran's vice-principal, Ken Maher, of the incident.

Paul Mooney, president of the National Parents Council Post-Primary, said: "I can understand the high spirits of Leaving Cert students as it's the end of their school days and they are excited.

"But there is no excuse for what happened in Kilkenny. The students got totally out of hand and it's not acceptable.

"It's very risky behaviour and someone could have been seriously hurt. It's up to both school principals to deal with the issue.

"I know the sixth-year students feel as if they are adults, but they seem to have exercised short-term thinking.

"Sixth-year students nationwide celebrating their last day in school before the exams need to conduct themselves properly."

A Kilkenny garda spokesperson warned that all Leaving Cert students should be aware of their conduct.

They added: "This type of conduct will not be tolerated as it so easily gets out of hand and can go terribly wrong.

"We would appeal to all students to celebrate in an appropriate manner."

Irish Independent