The Syrian Democratic Forces (SDF), a Kurdish-led militant group, has claimed it wouldn't try foreign militants and urged foreign governments to take them back.
According to Abdel Karim Omar, a senior official with the Kurdish administration in northern Syria, "around 520 Daesh* mercenaries, as well as 550 women and around 1,200 children from 44 countries" are still in Kurdish custody.
"It's a heavy burden that we can't carry alone," he said, as quoted by The Jordan Times, adding that the fighters were all foreigners. "We will not try any Daesh fighter," he stressed. "We are trying as much as possible… to pressure governments to carry out their duties and take their citizens back."
Kurdish fighters have formed the backbone of the SDF militia backed by the US-led coalition. The SDF has ousted Daesh fighters from swathes of Syria's north, capturing hundreds of them.
Their governments have barely shown any willingness to bring their restless citizens back. There have been some rare cases recently, however: it emerged that on Thursday, Syria's Kurds handed over a Sudanese woman arrested on suspicion of Daesh membership as well as her baby to a Sudanese diplomat after her country requested the transfer.
In August, Washington said the SDF had handed over two American citizens, who had allegedly supported Daesh, to US authorities.
The SDF fighters also hold "celebrity" detainees such as Alexanda Amon Kotey and Al Shafee Al Sheikh, two members of the notorious Daesh cell dubbed "The Beatles," who beheaded seven American, British and Japanese journalists and aid workers as well as a group of Syrian soldiers, releasing videos of the barbaric executions.
*Daesh (aka ISIL/ISIS/IS/Islamic State) is a terrorist group outlawed in Russia