Seven people have been injured – one critically – in a fire at a care home.
Emergency crews were called to the blaze at Woodlands View care home in Stevenage, Hertfordshire, at 16:30 GMT on Saturday.
Hertfordshire County Council said it appeared the fire was the result of a “minor explosion” caused by an oxygen cylinder.
One person is in a critical condition and six others are stable after being taken to Lister Hospital.
The fire was under control by 18:00 and all residents were evacuated from the building in Magpie Crescent.
A Hertfordshire County Council spokeswoman said: “There appears to have been a minor explosion caused by an oxygen cylinder but a full investigation will need to be carried out to confirm this.”
Hertfordshire Fire Service said the investigation was continuing and its crews would be at the scene “for some time”.
Eight fire engines, six ambulances and two air ambulances were sent to the scene.
The ambulance service said: “Ambulance crews have worked swiftly and effectively with colleagues in the police and fire service to evacuate the property and treat patients.”
Another 34 people were assessed by paramedics at the scene but did not require treatment.
Hertfordshire County Council said social services were working with the care home provider, HC-One, to move residents to alternative accommodation where necessary.