Germany repatriated on Saturday three women and 12 children from camps in northeastern Syria for humanitarian reasons.
Foreign Minister Heiko Maas said on Sunday he was "very relieved'' about the return of the children and three of their mothers.
"These are humanitarian cases, especially orphans and children with illnesses, cases in which the departure was urgently needed,'' Maas added.
'Further cases' to follow
"This good news just before Christmas makes us confident that we will be able to organise the return of further cases as well," he said, adding that the government would advocate the return of others in coming weeks and months.
Maas said the return was organised in cooperation with Finland, which repatriated six children and two women.
He did not further identify the women or children. However, the German weekly Bild am Sonntag reported that all three women had left Germany in recent years to join the so-called Islamic State group Syria. The paper identified the women as Merve A., Yasmin A. and Leonora M.
Woman arrested upon arrival
Germany's federal prosecutor's office said on Sunday that a German citizen named Leonora M. had been arrested upon her arrival at Frankfurt airport.
The woman is accused of membership of the terrorist group Islamic State and crimes against humanity.
Hundreds of Europeans -- including young women -- left the continent in recent years to join the ranks of the so-called Islamic State group in Syria and Iraq.
Several died, while others were arrested and detained by Turkish, Kurdish or Iraqi authorities, who have been eager to deport them and their children back to Europe. European governments, however, have been reluctant to take back their often radicalised citizens.