Police have named the NHS worker stabbed to death in a psychiatric hospital as health care assistant Sharon Wall.
She died following an incident at Wotton Lawn Hospital in Gloucester yesterday morning.
Gloucestershire Police said magistrates have authorised a further 36 hours for detectives to question a 60-year-old man arrested on suspicion of murder.
Detective Chief Inspector Steve Porter, the senior investigating officer, said: "The family are extremely distressed at the tragic loss of their loved one and have asked for some privacy and time to grieve during this difficult period."
Ms Wall, from the Tuffley area of Gloucester, was attacked at the inpatient unit at around 7.30am yesterday.
She was attended to by fellow clinicians before being taken to Gloucestershire Royal Hospital, where she died from her injuries an hour later.
A spokesman for 2gether NHS Foundation Trust said: "A tragic incident took place at one of our inpatient units in Gloucester yesterday morning.
"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.
"The full facts of this sad incident are still being established and therefore it is inappropriate for us to comment further at this time."
The 2gether website said Wotton Lawn Hospital was an 88 bed acute mental health hospital near the centre of Gloucester which provided inpatient services for the county of Gloucestershire.
The hospital has four admission wards, a nurse led psychiatric intensive care unit (PICU) and a low secure unit (LSU).
It said service users were supported by a variety of healthcare workers including nurses, doctors, psychologists, art therapists, physiotherapists, occupational and sports exercise therapists.
Health Secretary Jeremy Hunt said: "The events in Gloucestershire are devastating and our thoughts are with the family, friends and colleagues of the staff member involved."
People have paid tribute to the NHS worker on social media.
Tania Daniels wrote on Facebook: "I'm in shock. My thoughts are with your family. RIP lovely lady. I'll remember the times you came to my house years ago we had some good laughs and chinwags."
Anastasia Stacie Shields wrote: "She was an amazing lady. It's a real tragedy."
Kerry Louise Daniels wrote: "RIP Hun always in my thoughts. Fly high and shine bright." Abigail Harris wrote: "RIP my darling angel! Such a lovely lady who will be seriously missed by all the family."
Hayley Robertson wrote: "Awful to happen to a member of the NHS, so sad. Heard all the sirens on the way to work this morning. Can't believe this has happened right outside where I work - such a tragedy. My thoughts and prayers are with the family."
Michelle Sansom added: "Such sad news. RIP poor lady, my thoughts and prayers go to your family and friends and all the staff as well."
Workers at Gloucestershire Royal Hospital, on the same site as Wotton Lawn, have spoken of their "shock" at the incident.
Denise Luckman, 44, an admin assistant at the endoscopy unit, said: "I've worked here for 10 years and nothing like this has ever happened.
"It has been a huge shock to everybody.
"You don't expect to go to work, to care for patients, and to have that happen.
"It has affected the hospital all the way through.
"It is on our own doorstep, it has come as a complete shock."
Mrs Luckman said staff across the hospital often worked in different units to help short-staffed wards, including Wotton Lawn.
"All the staff are very subdued," she added. "It just shows that these things can happen."
Chief executive of 2gether NHS Foundation Trust Shaun Clee said: "We are all deeply shocked by the tragic incident that occurred on one of our inpatient wards yesterday morning.
"The extremely sad event, which resulted in the death of a highly compassionate and dedicated colleague, has had a profound impact on everyone working in our trust.
"Sharon Wall was a well-respected healthcare assistant and everyone who knew her speaks about her warmth, caring nature and good sense of humour.
"She will be deeply missed by colleagues and the service users she supported.
"We are still in the early stages of the investigation and continue to assist Gloucestershire Police in their work.
"Above all, our thoughts remain with Sharon's friends and family. On behalf of colleagues across our trust, I extend our most sincere and deepest sympathies."