The case of three children believed to be from the UK, trapped in Syria after their parents joined the “Islamic State group” and subsequently died, has raised questions about how they can be repatriated.
The children, Amira, Heba and Hamza, were featured in a recent BBC report from a Syrian camp for the families of IS fighters.
So what's the procedure for repatriating them – and what are the difficulties?
Diplomatic access
The camps in northern Syria holding IS families are currently controlled by Kurdish-led forces whose leaders have repeatedly asked European countries to take back their nationals.
Many countries have been reluctant to readmit IS supporters both because of public opinion and legal issues.
Foreign nationals abroad are entitled to some form of consular assistance and this would normally require direct contact with those being held in the camps.
However, this is complicated by the fact that many countries have closed their embassies in Syria.
Some countries have also made clear that they believe it's too dangerous to send their officials into a war zone.
As the conflict escalates in northern Syria, the levels of insecurity in and around the camps makes this an increasing problem.
