A man and three children have died in an explosion at a family home.
The blast happened in Hillside Road in Cheddleton, near Leek, Staffordshire, and developed into a severe fire.
Six houses surrounding the home were evacuated because of the blaze on Thursday night and part of the road remains sealed off on Friday.
Staffordshire Police said the dead were all from the same household. A man in his 30s has been arrested in Leek in connection with the explosion.
Officers are investigating reports of a man seen running from the scene.
Investigations by police and fire officers are continuing at the scene, but officers are being hampered by the unsafe structure of the house.
CCTV pictures recorded from a neighbour's garden, obtained by the BBC, show the moment the explosion happened, followed by at least two other blasts.
Eye-witness Audrey Spooner said: "It was just an inferno, I've never seen anything like it."
Roy Spooner said: "There were flames coming out of the roof and there was like fire balls coming out from above the windows."
Staffordshire ambulance service said it was first alerted by a call saying there were "sounds of some form of explosion from the property and screams".
Ch Insp Ken Raiper, of Staffordshire Police, said: "It is a scene of extreme devastation. We are in the process of trying to make the premises safe.
"We need to carry out some forensic and expert examinations of the area."
Staffordshire fire service's Neil Backes said: "The rear of the property has suffered some form of explosion damage we are as yet unsure of the cause of that damage.
"The rear of the property is very severely damaged as is the first floor and the fire has gone through the roof and made the first floor unsafe.
"It's a tragic situation. Our officers tend to rely heavily on their experience during these times.
"It's not something we're unaccustomed to, but it never ceases to surprise and shock us when these things happen."