Police have extended a search area in the continued hunt for four escapees on the run from Campsfield House immigration centre.

The four men, whose pictures have been released by police, escaped from the detention centre near Kidlington at some time last night, with their disappearance only noticed at 3.30am.

Three other escapees were recaptured and one is under police guard at the John Radcliffe Hospital.

Speaking outside Campsfield House, Inspector Graham Sutherland urged local people to remain vigilant and report any suspicious behaviour or men he described as appearing disorientated.

There are 22 officers searching the area but every police officer in the county who has been issued with new BlackBerry devices has been sent photographs of the four wanted escapees, Mr Sutherland added.

He said said: "The search continues and anything goes - from out-houses, hedgerows, ditches, the lot. Everything is covered until we are happy they are cleared and we can move on.

"We are keeping an open mind as to whether the men are in the area or have gone further afield but we have extended our search area.

"Officers are also searching and patrolling local villages to reassure people and to pick up any information."

Police with search dogs were in the area at 5am and the force helicopter has been in the air scouring the countryside below.

Officers have been searching land south of Campsfield House at Begbroke where it is believed the men made their escape.

Three of the escapees were awaiting deportation at the immigration centre and had not committed any crimes.

They were two men from Palestine and one from Afghanistan.

But the fourth escapee, from Libya, had served time in a British jail for theft and assault.

Insp Sutherland added: "We would not describe them as dangerous and from the information we have they are low risk.

"But we do not want the public to approach them and getting into situations they should avoid."

Senior police officers are meeting Borders and Immigration officials and managers at Campsfield House today to talk about security.