A three-year-old boy and two teenagers are fighting for their lives in Exeter hospital after a blaze in a Honiton property with eight people inside.
All but one of the eight people are believed to be from the same family.
At around 7.48am emergency services were called to a reported house fire at a property in Lee Close, Honiton.
A three-year-old boy, a 17-year-old girl and an 18-year-old man sustained serious injuries and were taken to Royal Devon and Exeter Hospital.
The three-year-old boy sustained serious injuries and has been transferred to Frenchay Hospital , Bristol. The hospital has a specialist burns unit.
A six-year-old boy and a man in his 30s are also being treated in hospital for smoke inhalation.
The air ambulance and the police helicopter also attended the scene, assisting in the evacuation of the casualties to hospital.
Neighbour Dave Josling, a former fire fighter, said he was woken up at about 7.30am to fire engine sirens.
“I looked out of my window and saw smoke billowing out of the upstairs window and thought, I hope no one’s hurt.
“When I saw five fire engines outside, I knew it was serious.”
Another shocked neighbour, Derek Bradley 72, said: "They are a nice family but not many people know them, they keep themselves to themselves.
"They've only been here two or three months. They are quite a big family, or so I think they are.
"It seems as if they have dozens of kids in that house at times. I don’t know how many
were inside at the time."
The fire has been extinguished however police and fire investigators remain at the scene.
Police commander Paul Davies, speaking from the scene, said: “There is nothing to suggest the cause of the fire is suspicious. But now there is a multi-agency approach to determine the cause."
Adding: "Two young adults and a young child were taken to hospital. The other five are either at a hospital, being looked after by police or are with friends. It is understood a family member in the house raised the alarm. The house is badly damaged."
Video: Police commander Paul Davies, speaking from the scene
Police have taped off the area around Lee Close, preventing anyone coming or going from the road.
A representative for the south Western Ambulance Service said:
"“South Western Ambulance Service (SWASFT) was called to a residential property in the town of Honiton after being notified by fire service colleagues at 0736 today.
“The Trust immediately dispatched a number of vehicles including one of the Devon air ambulances. Five ambulances and two officers were also promptly on scene, with the first vehicle arriving within four minutes.
“Members of the Hazardous Area Response Team (HART) were also in attendance. These highly trained paramedics have specialist equipment to deal with this type of situation.
“A number of casualties were treated at the scene for smoke inhalation. Four people, all thought to be in a life-threatening condition, have been taken to the Royal Devon and Exeter Hospital.”