Ten people have died and seven are being treated in hospital following a fire at a nursing home.
Crews were at the scene within minutes
Firefighters were called to Rosepark Care Home in Uddingston, near Glasgow, at 0437 GMT on Saturday.
Emergency crews said an "intense" fire broke out in a top floor cupboard in the home and generated a lot of smoke.
About 23 or 24 residents who were in the privately-run home at the time and were unhurt have been moved to another home nearby.
The Scottish Ambulance Service said 10 people had died at the scene.
Ten people were thought to have been taken to hospital immediately after the fire and seven were still undergoing treatment.
Casualties were taken to Monklands Hospital, Wishaw General Hospital and Glasgow Royal Infirmary.
Police said three were critically ill.
Chief Superintendent Tom Buchan said: "About 4.40 this morning we first received information that there had been a fire at Rosepark Nursing Home and in attendance were fire and police officers.
"Unfortunately we discovered there had been a significant number of fatalities."
He told reporters: "There is cause for concern for at least one person in hospital, bearing in mind these are elderly people.
"It was not as you would call a significant fire in the sense the premises were destroyed.
"There is in fact very little damage."
Mr Buchan said an incident room has been set up and officers were offering assistance to concerned relatives.
A dedicated helpline set up for friends and families of residents at the privately-run home has already received more than 300 calls.
Alan Forbes, of Strathclyde Fire Brigade, said: "Firefighters discovered a small but intense fire in one of the wings, which is quite a new building, a purpose-built care home, which opened in 1992.
"Over 40 firefighters assisted ambulance crews in getting casualties out of the building and into the ambulances."
Strathclyde firemaster Jeff Ord said the procurator fiscal, fire investigators and forensic pathologists were involved in the investigation.
"Every resource is being put into this major incident," said Mr Ord.
"I believe this is the largest loss of life at any registered premises since the 1960s."
Mr Ord said smoke alarms were sounding when firefighters arrived.
The 43-bed home is in New Edinburgh Road is owned by Tom and Anne Balmer.
In a statement, they said: "Everyone connected with the home is devastated by this morning's tragic loss of life.
"Our hearts go out to the families and friends of those who have lost their lives or who are now in hospital.
"Our staff and ourselves are shattered by this loss of life. We consider all our residents as part of our family and many have been with us for a number of years."
Rosepark houses elderly and infirm people on a short stay and long stay basis.
It also offers day care, respite care and care for terminally ill people and people with psychiatric conditions.
The two-storey residence opened in 1992 and people living in homes nearby spoke of its excellent facilities.
Seven people have been taken to hospital
Police cordoned off a stretch of New Edinburgh Road as the investigation into the fire got under way.
Barbara Maclennan, director for services at Carrick Care Homes, offered beds at nearby Highgate Care Home in Uddingston to Rosepark residents.
Croftbank House, in Uddingston, said a number of elderly people from Rosepark had been transferred there, then moved to other facilities.
A spokesman for the Care Commission, which regulates all care homes in Scotland, said the last main inspection of Rosepark was in February last year. There was a further visit in November.
On both occasions, the commission was satisifed with safety procedures.
The helpline number for relatives is 01698 483 200.