The couple from Shrewsbury took the youngsters from social services staff during an arranged contact meeting at social services office in Wem High Street on Saturday afternoon.

The family were seen trying to pay for petrol at a garage in Whitchurch Road, Shrewsbury, with euros.

They were spotted in a white Peugot 205 car, registration E512 FLE, on Saturday afternoon.

Social services are concerned for their welfare

Detectives investigating the abduction believe this is an indication that they were preparing to leave the country.

The abducted children are 12-year-old Tara Richards, her three brothers Tadhg, who is eight, Charlie, four, and Sid, three.

Sharon Richards, 35, and Steven Hayward, 33, took the children just before 1400 GMT.

They say the children have been in care for some time and although they are with their parents, they are treating the matter as an abduction.

We do have concerns for their health and welfare and want to find them as quickly as we can so we can return them to their carers and continue with court proceedings Terry Jones, from Shropshire Social Services

Detective Inspector Charlie Hill, from West Mercia Police, said: "We would appeal to anyone who sees a family who they haven't seen before in their locality, fitting this description.

"If they don't know them and the children all speak with Irish accents then please contact the police"

All four children were under the care of social services and had been seeing their parents at supervised meetings on a weekly basis.

He said he believed the family may have fled to Ireland where Mrs Richards has relatives and sea and air ports had been alerted.

The children were taken from Wem High Street

A police spokesman said the parents were late arriving for the one hour meeting on Saturday afternoon.

When they did arrive it was agreed they should have a 10 minute meeting with the children.

He added a short time later, the family left the building.

An internal inquiry has been launched by Shropshire County Council's social services department.

Terry Jones, from Shropshire Social Services, said: "The children have been in our care for just over 12 months.

"We do have concerns for their health and welfare and want to find them as quickly as we can so we can return them to their carers and continue with court proceedings."

Scruffy appearance

Mr Hayward is described as being about 5ft 8in tall, of slim build with green eyes.

He has several tattoos including a bird of paradise and the word "Steve" on his left arm and the words "Dagger, born to lose" on his right arm.

He speaks with a Midlands accent.

Mrs Richards is 5ft 2in tall and of very slim build with blue eyes, shoulder-length light brown, straight hair and has a scruffy appearance.