Germany has repatriated several children of jailed Islamic state militants from Iraq, the foreign ministry said on Friday.
"The number of minors already brought back to Germany has reached a high single-digit figure," told AFP.
The children were returned with the consent of their parents, the source added.
Among the first young returnees to Germany were three children who arrived with their 31-year-old mother at Stuttgart airport on Thursday, their lawyer Mahmut Erdem said in a statement.
They were taken into custody immediately, the lawyer said.
According to the Foreign Ministry, at least eight Germans were jailed in Iraq, after they were convicted over their membership of ISIS.
The Foreign Ministry said it was aware of cases of German nationals in custody in northern Syria, but added that it did not have direct consular access to them as the embassy in Damascus has been closed.
Nevertheless, the government is looking for ways to repatriate the German nationals, it added.
With the collapse of the last ISIS stronghold in the village of Baghouz in Syria last month, the fate of foreign fighters and their families has become a significant problem for governments as the conflict against ISIS draws to a close.
France last month took in five orphans and is dealing with returns on a case-by-case basis. The French government said it made the decision to return the children because they were “very young and especially vulnerable”, before thanking the Syrian Democratic Forces for helping return them.
The UK, on the other hand, has refused to evacuate foreign fighter children from Syria, citing security concerns. The ISIS recruit, Shamima Begum, has been stripped of her citizenship and authorities did not intervene when she gave birth to a child who died of pneumonia in a Syrian refugee camp last month. British Foreign Secretary Jeremy Hunt has warned to the obstacles to repatriation. "We have to think about the safety of the British officials that I would send into that war zone," he said.