Praise be to Allah.
With regard to the children, the Muslims are obliged to take care of them and bring them up in Islam. They must not leave them to the Christians or others. As Allaah says (interpretation of the meaning):
“The believers, men and women, are Awliya’ (helpers, supporters, friends, protectors) of one another” [al-Tawbah 9:71].
And the Prophet (peace and blessings of Allaah be upon him) said:
“The likeness of the believers in their mutual love, mercy and compassion is that of the body: when part of it is in pain, the whole body joins it in staying awake and having a fever.”
And these children come under the ruling of orphans, and Allaah has prescribed kind treatment to orphans in particular.