Eye-witness accounts from Yarl's Wood
People living near to the Yarl's Wood detention centre have been watching closely as police and firefighters continue to surround the charred remains of the building.
Many were woken overnight by the sound of helicopters and sirens.
A campaigner against detentions at Yarl's Wood said he had been inside the centre when the first signs of trouble broke out.
Mike Gilmour, of the Campaign to Stop Arbitrary Detentions at Yarl's Wood stood outside all night, watching fire engines and police cars form around the centre.
He said he was alerted to the seriousness of the fire after phone calls from frightened inmates.
"The only thing we are aware of that could have sparked any trouble was this 55-year-old woman.
"For three days she had been seeking to get medical treatment. Last night she was handcuffed in preparation to take her for treatment and she obviously objected to it.
"It has been suggested that this is the final straw that sparked it off."
The police have been able to confirm the incident.
The campaigner had been visiting the centre when he was asked to leave at about 2015 GMT.
He started getting phone calls from the detainees 10 minutes later.
"People were calling last night. Initially they were saying they were very frightened.
"They were saying that there was an altercation going on. They said they had moved out of the building but the fact that the police had come in, that was concerning them.
"People were being taken out of their bedrooms. They are indoors all the time, so they have no outdoor clothes. They could well have been out there in their indoor clothes in sub-zero temperatures.
"All night we kept seeing security vehicles taking people out of the centre.
Local residents were alerted to the incident by the sound of police helicopters overhead.
Molly Foster, who lives near the centre, said she has been afraid for some time that this kind of problem could arise.
"Other people in the village rang up the police and they said there could be up to 30 or 40 people on the run," she said
"Now I don't know whether they have any idea how many people escaped and that is very worrying in itself. "In the village we're extremely worried, obviously all night long. "We were told to lock the doors and make sure every thing was secure." Cliff Smith, who lives on a farm near Yarl's Wood, said he first realised something was wrong when his dog started barking. He says he then heard a police helicopter overhead which led him to believe that someone had escaped from the centre. "We have always been concerned that people might get out but we were told time and time again that no way. "That there's a 15ft fence there with a razor around the top of it and then another fence around that - the old Ministry of Defence fence - and we assumed that no-one would ever get out of the place, but I mean obviously no-one considered a fire like this, did they?"