Just last week, Home Secretary David Blunkett admitted one centre in particular was "outdated".

He told the House of Commons that Campsfield House in Oxfordshire is to be closed because it is "no longer appropriate in the 21st Century".

The centre, which houses up to 200 asylum seekers and like Yarl's Wood is run by security firm Group 4, has been the scene of fires, riots and hunger strikes since it opened in the mid-1990s.

Last September, about 90 detainees went on hunger strike, complaining that they were being treated like prisoners when they had done nothing wrong.

Frustration

Then in November, five refugees were injured when fires were deliberately started at the centre.

At around the same time, similar trouble was brewing at another centre, Haslar in Gosport, Hampshire.

There, around 75 detainees held a peaceful sit-in, refusing to carry out their normal activities.

Frustration at being locked in and the prospect of deportation is thought to have fuelled the protest at Yarl's Wood.

Chapfika: 'Detainees have committed no crime'

Former Yarl's Wood detainee Codson Chapfika told the BBC: "I've been friends with most people in there and not one of them that I came in contact with committed any crime.

"Imagine that these people are being detained for an indefinite period of time without committing any crime."

In the wake of the Yarl's Wood disturbances, the UN High Commissioner for Refugees condemned the practice of mixing people who were being deported and people who still did not know their fate.

Spokesman Kris Janowski called it a "recipe for problems".

Human rights

The Refugee Council in Britain said 50% of detainees had not had an initial decision made on their asylum claims.

"The key to resolving the tensions that inevitably occur in detention centres is to ensure people feel they have access to a legal redress for what they feel is their unjust detention otherwise they will be left feeling the situation is hopeless," said Chief Executive Nick Hardwick.

The wave of unrest in the later part of last year was sparked by a High Court decision that four Iraqi Kurds were being held unlawfully at Oakington fast-track immigration centre in Cambridgeshire.

The judge ruled that detaining the men - who were neither likely to abscond and were not being deported - breached human rights laws.

The Court of Appeal later over-turned the decision but it sparked a massive overhaul of the system for dealing with asylum seekers.

Asylum seekers are fast-tracked through Oakington

There are currently seven detention centres which have been re-named immigration removal centres: Campsfield House in Oxfordshire, Tinsley House in Sussex, Harmondsworth, nr Heathrow, Dungavel in Lanarkshire, Yarl's Wood in Bedfordshire, Lindholme in Lincolnshire and Haslar in Hampshire.

Like the people staying at Yarl's Wood, the 2,890 detainees in removal centres know their bid for British residency has failed.

In addition, there is an induction centre at Dover in Kent, where around 600 newly arrived refugees claiming asylum are housed while they are processed.

In new measures announced by Mr Blunkett last October, there will also be a middle tier of holding centre for those whose claim is being considered.

Eight sites are under review for these accommodation centres where food and board will be available, along with healthcare and education.

People will be able to come and go but there will be no other form of support for them if they decide to leave.