A member of staff has died after being stabbed at a mental health hospital in Gloucester.
The female victim, who has not been named, was attacked at the inpatient unit at Wotton Lawn Hospital.
A man in his sixties, believed to be a patient, was arrested on suspicion of murder and remains in police custody.
Health Secretary Jeremy Hunt said: "The events... are devastating and our thoughts are with the family, friends and colleagues of the staff member."
A spokesman for 2gether NHS Foundation Trust described the situation as "tragic".
He said: "During the incident a colleague was stabbed and after being attended by fellow clinicians, was taken to Gloucestershire Royal Hospital.
"It is with deep sadness that we confirm that our colleague died a short time later. Our thoughts remain with their family and friends at this extremely difficult time."