A boy held over the stabbing of a teacher in Tewkesbury was arrested on suspicion of attempted murder, police have said.
Firearms officers arrested the teenager an hour after the stabbing in Stoke Orchard, about five miles south of Tewkesbury, and recovered a knife.
Specialist resources including the National Police Air Service were deployed to track the suspect down.
The teenager is from Tewkesbury, police said in an update outside the school on Monday afternoon. His age was not given and he remains in custody.
Motivation remains unclear, but it is not thought to be terrorism-related. No one else was injured.
Police were called just after 9am on Monday over a "threat to a teacher", Assistant Chief Constable Richard Ocone told reporters.
"Minutes later we received a call from the ambulance service telling us that a male teacher had been stabbed in a corridor at the school," he said.
"He was taken to hospital with a single stab wound and remains in a stable condition."
