A female teacher is among the three people stabbed by a girl at a high school in Wales.

Dozens of police cars and helicopters were sent to Amman Valley School in Carmarthenshire, south-west Wales, while classrooms were put under lockdown.

One person has been arrested, police said.

The injured teacher was flown by air ambulance 70 miles to the University Hospital of Wales in Cardiff.

A pupil, believed to be in the same class as the suspect, was given first aid at the school until paramedics arrived.

Parents are anxiously waiting outside for their children, who are reportedly being held inside as the school remains on “code red”.

It was initially unclear who the third victim was but people gathered outside the school suggested there may have been another member of staff who was injured when they tried to intervene.