The asylum children plans have sparked controversy

The Prison Service document comes after unannounced inspections of three London centres and one in Salford.

A lack of access to telephones for detainees and lack of child protection policies were also criticised.

In response, Home Office Minister Des Browne has pledged to introduce policies on child protection and extend independent monitoring systems.

He said: "Detention is an essential part of effective immigration controls, but vital that it is done with humanity and dignity, and I am committed to ensuring this."

Suicide prevention

Mr Browne said he would consider all the recommendations made in the report.

Anne Owers, Chief Inspector of Prisons, said procedures and practices were needed to ensure the centres were "safe and decent environments".

She also said staff were "alert" to the notion that people were being held at the centres "at a time of considerable stress".

The report, carried out between June and October 2004, looked at Dallas Court in Salford, Lunar House and Electric House in Croydon; and Communications House in east London.

It found staff lacked training in prevention of self-harm and suicide, and said there were no fire or health and safety policies or procedures.

'Unfit for purpose'

There was not enough for detainees to do, or to read, and there were no arrangements for them to recover or dispose of their property.

However, inspectors observed that staff treated detainees well and tried to minimise their stress.

Particular problems were identified with Dallas Court where the holding room was described as cramped, shabby and "unfit for purpose".

Immigration staff were not always informed about detainees being moved and on one occasion inspectors found a young woman, held for six hours, who had recently miscarried and was at risk of suicide.

Inspectors said staff at Lunar House were "not alert to the need to ensure safeguards on the detention of children were implemented."