Two teenage girls have been arrested on suspicion of planning to murder a teacher.
Gwent Police said the girls, 14 and 15, were arrested at Cwmcarn High School in south Wales on Thursday because of concerns about their behaviour.
Detectives said they were notified about the alleged plot by a teacher at the school.
A force spokesman stressed "no physical confrontation" had taken place.
The 15-year-old girl was arrested on suspicion of threats to kill, possession of a "bladed article" on school premises and conspiracy to commit murder.
It is believed a kitchen knife had been found in the girl's school bag.
Her 14-year-old friend was arrested on suspicion of conspiracy to commit murder.
A statement on the Cwmcarn school's website from head teacher Jacqui Peplinski said: "You may be aware that concerns were raised about a pupil in the school yesterday.
"Please be assured that the concerns were dealt with swiftly. There was no risk to any staff or learner and the relevant support services were contacted as a precautionary measure.
"Cwmcarn High is a caring and safe environment and we are committed to everyone's safety. Please do not hesitate to contact us if you have any concerns."
The alleged murder plot comes less than a week after Ann Maguire, 61, died following a classroom attack at Corpus Christi Catholic College in Leeds.
Gwent Police said in a statement: " Officers were called to Cwmcarn High School at approximately 11:54am on Thursday May 1 following concerns being raised about the behaviour of two pupils.
"Officers attended and arrested two girls, aged 15 and 14.
"They have since both been released on police bail pending further inquiries.
"Nobody was harmed as a result of the incident, and the matter was resolved peacefully."