More than 2,500 children from more than 30 countries are living in three camps for people displaced in north-eastern Syria, Save the Children says.

The agency revealed the figure as it argued for Isis bride Shamima Begum, who is living in a camp, to be allowed to return to Britain.

Ms Begum, 19, who left her home in London to join Isis as a 15-year-old schoolgirl, was stripped of her British citizenship after she asked to come back with her newborn baby.

Save the Children says the 2,500 youngsters, “from families with perceived or actual links with Isis”, are separated from the rest of the population in the camps, which hinders their access to aid and services.

Most are living with their mothers, while unaccompanied children are with temporary caregivers, the charity says. In some cases, foreign girls recruited by Isis as children are now mothers themselves.

Syria at war: Fleeing the caliphate Show all 14 1 /14 Syria at war: Fleeing the caliphate Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria Richard Hall/The Independent Syria at war: Fleeing the caliphate Zikia Ibrahim, 28, with her two-year-old son and 8-month-old daughter, after fleeing the Isis caliphate Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Men who fled the last Isis-held area of Syria line up to be questioned by American and Kurdish intelligence officials Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate A young girl pulls her belongings after arriving Richard Hall/The Independent Syria at war: Fleeing the caliphate An SDF fighter hands out bread to women and children after they arrive Richard Hall/The Independent Syria at war: Fleeing the caliphate Sita Ghazzar, 70, after fleeing from the last Isis-held territory in Syria Richard Hall/The Independent Syria at war: Fleeing the caliphate A family from Russia who recently fled the last Isis-held area of Syria Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Richard Hall Richard Hall/The Independent

The children in the camps are facing life-threatening risks, according to aid workers.

Kirsty McNeill, of Save the Children UK, said: “All children with perceived and actual associations with Isis are victims of the conflict and must be treated as such.

“We believe the best interests of the child are paramount and this means a child and mother should remain together whenever possible.

“Shamima Begum was radicalised as a child. She is now in a camp with her baby, surrounded by former Isis members. It is crucial we get her back to Britain and a safe place to understand more completely what has happened to her.”

As the territory held by Isis shrinks, civilians have flooded out. More than 20,000 have escaped over the past month, according to an official.

Since January, 560 foreign families, with more than 1,100 children, have entered the camps alongside thousands of Syrian families.

The shrinking Islamic State caliphate has been under intense bombardment and cut off from food supplies since December.

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Escapees have told how they had not eaten for days when they reached the camps.

The International Rescue Committee said 62 people had died en route from hypothermia, hunger and illness. Fifty of them were children, most under the age of one.