Updated

France's government has quietly backtracked on a policy that allowed children to leave the country without their parents' permission, after years of complaints from families of radicalized teens who left to join extremist groups.

The new rules requiring parental permission go into effect Sunday, five years after the government lifted the restriction with little fanfare, citing a need to streamline bureaucracy.

At the time, the war in Syria was picking up and France became Europe's largest source of recruits in the war zone, notably for the Islamic State group. Families said they were blindsided when their teenage sons and daughters were allowed to pass through border control no questions asked and even leave Europe's passport-free zone for Turkey.