The pupil was attacked at Thorpe St Andrew School at about 10.20am on Wednesday (March 11) and was taken to the hospital with "minor injuries".

Pupils were told to hide under desks and the school bell could be heard ringing out across the site for hours.

It is understood that teachers told pupils not to go on their phones at the time, but after being in lockdown for more than an hour, pupils were then allowed to message their families.

A 15-year-old boy has been arrested on suspicion of causing grievous bodily harm with intent.

He has been taken to Wymondham Police Investigation Centre for questioning, where he remains this morning.

A letter sent to parents on Wednesday evening said: "When something like this happens, routines and normality are helpful, and so school will be open as normal tomorrow (Thursday) at 8am.

"However, if you as a family wish to support your child at home we will respect this choice."

The police and a support team from the local authority will be on site to reassure pupils, staff and the wider community.

Broad Horizons Education Trust, which runs the school, say it will take time for pupils and staff to process what happened, supporting each other to come through it.

A spokesman for Broad Horizons Education Trust, said: "We have clear procedures in place and our staff acted swiftly, with the whole school going into lockdown with children staying in their classroom with their teacher.

"One of our students was injured and is now being treated in hospital for minor injuries.

"This has obviously been a distressing experience for our whole community and our focus now is on making sure all students feel supported as we begin to understand what happened."

© Eastern Daily Press