Reports from parents with children at Thorpe St Andrew School have indicated they believe the girl may have been attacked randomly, rather than deliberately targeted.

The pupil was stabbed at about 10.20am on Wednesday and taken to the hospital with "minor injuries".

A photo of an armed officer inside the school (Image: Supplied)

A 15-year-old boy - described as white British - was arrested on suspicion of causing grievous bodily harm with intent in Pound Lane, just metres from the school, after a short time on the run.

Pupils were told to hide under desks, teachers barricaded classroom doors with cabinets, and the school bell rang out across the site as armed police swooped through the hallways.

It is understood that the suspect jumped over the school fence at the south site entrance in Laundry Lane to escape the scene.

READ MORE: Live updates as cordon remains in place near school after stabbing

A student, who managed to make contact with their family via text message amid the schoolwide lockdown, said: "I am very scared".

Another pupil simply said that they "just want to go home".

A spokesman for Broad Horizons Education Trust, which runs the school, 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.

A picture of the 15-year-old being arrested in Pound Lane (Image: Supplied)

"One of our students was injured and is now being treated in the 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."

A Norfolk Constabulary spokeswoman has confirmed that "reassurance patrols" will be carried out at the school and in the surrounding area over the coming days.

She added that the stabbing is not believed to be linked to an antisemitic hate crime that occurred during an under-15s football game at the school last Thursday.

© Eastern Daily Press