A 15-year-old boy has been arrested after an alleged threatening email sent to a member of staff led to a school being closed.
Police investigated the threat and searched Wyvern St Edmund's secondary school in Salisbury, Wiltshire.
The boy has been arrested on suspicion of communicating false information and is in custody.
The school has said it is reopening for Thursday and police said they will have patrols there for reassurance.
The latest school statement said: "The potential security threat has been found to be a hoax and is being dealt with as a police matter.
"They have now given the all clear for a safe return."
It added that the incident was "not connected to any member of our school community".
