A 15-year-old boy has been arrested after a woman teacher, 61, was stabbed to death at a Leeds school.
The member of staff at Corpus Christi Catholic College in Neville Road, Harehills, named locally as Anne Maguire, was fatally injured this morning.
It is understood she was attacked in a classroom and stabbed a number of times in the back.
West Yorkshire Police detectives said a 15-year-old boy was arrested in connection with the incident and remains in custody.
Detective Superintendent Simon Beldon said there was no ongoing risk to pupils or staff and that the school was "continuing to operate as normal".
He said: "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.
"The rest of the school is continuing to operate as normal and we would ask that parents do not attend the site unless directly requested to do so by the school.
"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."
Police were called to the school at 11.48am after they were contacted by the ambulance service following a report that a member of staff had been stabbed.
The woman was taken to hospital for treatment but was subsequently pronounced dead, police said.
A 15-year-old boy, a pupil at the school, has been arrested in connection with the incident and is currently in custody.
Christine Blower, general secretary of the National Union of Teachers, said: "This is a truly awful thing to have happened to a teacher in the course of her work to educate the next generation.
"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.
"The NUT will provide any help and assistance we can possibly offer to Corpus Christi Catholic College and its community."
Russell Hobby, general secretary of the National Association of Head Teachers, added: "We are shocked and saddened to hear the news that a teacher has been stabbed to death at Corpus Christi Catholic College in Leeds.
"Our thoughts are with her family, her colleagues and the students of the school.
"Teachers carry a great weight for our society and we owe them so much.
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."