The French families accused the government of “arbitrary detention” and “abuse of authority”, their lawyers said.
The question of what to do with the 40 or so Islamic State (ISIS) jihadists – men and women accompanied by 20 children – arrested following the collapse of the caliphate – has sparked heated debate in recent weeks. Their fate, however, remains a question mark.
By refusing to repatriate them, French authorities are “exposing these mothers and their children to obvious risks, namely sanitary ones, in a conflict zone”, the lawyers added.
While the French government announced earlier this month ISIS militants arrested in Kurdish-held Syria should be tried locally, their lawyers argue they should be sent back to France as they cannot be guaranteed a fair trial in Syria.
Lawyers Marie Dosé, William Bourdon, Martin Pradel and Marc Bailly said: “These women who went out there are the object of legal proceedings in France and are willing to face up to their criminal responsibilities back home.”
Syrian Kurdistan is not a legally recognised state, the lawyers argued, adding the women and children were being held in unauthorised detention.
Mr Pradel: “A fair trial is one that is overseen by an independent, impartial judge whose decisions are based on a constitution. But there is no such thing as a Kurdish constitution.”
The lawyers did not say how many families were involved in the lawsuit, and it remains unclear whether former ISIS recruiter Emily König is among the plaintiffs.
Mrs König, a 33-year-old Muslim convert from Brittany, was arrested by Kurdish forces in Syria in December and is currently being held in a refugee camp along with her three youngest children.
The Frenchwoman, who fled to Syria in 2012 and was featured on a UN terrorist blacklist, has asked to be tried at home in France.