Ysgol Dyffryn Aman, in the Welsh town of Ammanford, was sent into lockdown on Wednesday after a 13-year-old girl allegedly attacked multiple people at the end of morning break.
Children as young as five have been revealed to be bringing blades into their classrooms, with one charity boss branding the battle a cancer that is spreading across the country.
Headteacher James Durbridge has praised staff and pupils for a calm and mature response after a 14-year-old girl went mad with a knife in the playground.
Year 9 girl who tried to stab teacher at Ammanford school has been in trouble in class before dailymail.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from dailymail.co.uk Daily Mail and Mail on Sunday newspapers.