A teacher at a school in Leeds was stabbed to death this morning and a 15-year-old pupil has been arrested in connection with the incident.
The female member of staff, who has been identified as 61-year-old Spanish and religious education teacher Ann Maguire (pictured), was fatally injured this morning following an attack at Corpus Christi Catholic College.
Officers were called to the school shortly before midday by the ambulance service and the woman was taken to hospital, where she was pronounced dead.
West Yorkshire Police detectives said a 15-year-old boy was arrested in connection with the incident and is in custody.
Detective superintendent Simon Beldon said that there was no ongoing risk to pupils or staff and the school was "continuing to operate as normal".
"The situation is under control and officers, including safer schools officers and members of the local neighbourhood policing team, are currently at the school and are liaising closely with staff,” he said.
And he added: "Our inquiries are at a very early stage but the full circumstances of this incident will obviously be the subject of a full and thorough investigation."
Prime Minister David Cameron joined those paying their respects to the teacher, described as a "mother figure" at the school.
Mr Cameron said: "My thoughts are with the family of Anne Maguire, as well as the staff and pupils of Corpus Christi school, where she was stabbed to death."
Christine Blower, NUT general secretary, said it was "a truly awful thing" to have happened to a teacher.
"Appalling events like this are thankfully very rare indeed, but the death of any teacher in her place of work, which should be a place of safety, is devastating. Our condolences go to the family and friends of this teacher, and to students and colleagues at the school," Ms Blower said.
Heads' union the NAHT said that it was "shocked and saddened" by the news.
"Teachers carry a great weight for our society and we owe them so much," NAHT general secretary Russell Hobby said. "It is terrible that they should be asked to pay this price too. We know that the close community of schools in Leeds will rally round to offer colleagues their support."
Pupil Georgina Kilroy, 16, said the woman had been a teacher for 40 years.
Speaking outside the school, she said: "I don't know anyone who didn't like her. She was spot on. You couldn't ask for a better teacher."
Georgina said her teacher broke down when she told the children the news. She said that before then they had been told that a teacher had gone to hospital, but lessons had continued as normal.
The incident has echoes of Philip Lawrence, headteacher at St George's Roman Catholic School in London, who was fatally stabbed outside the school gates by a teenage gang member back in 1995.
Mr Lawrence had gone to the aid of a 13-year-old student who was being assaulted by a gang outside the school premises.