Ayatollah al-Sistani prohibits the enslavement and rape of women during a military campaign, and forbids sex with non-Muslim concubines:

Fatwa, posted 4.22.2010, from Iraq, in:
Religious Authority: 
Ali al-Sistanti
Fatwa Question or Essay Title: 
Ayatollah al-Sistani prohibits the enslavement and rape of women during a military campaign, and forbids sex with non-Muslim concubines:

Is it permissible to enslave women belonging to infidels who make war [against us] without the permission of the legitimate ruler? Is it permissible to have sex with them before they surrender? And if someone bought or came to own a non-Muslim concubine, may he have sex with her?

Answer: No, it is not allowed.

نساء الكافر الحربي هل يجوز استرقاقهن دون اجازة الحاكم الشرعي؟ وهل يجوز وطؤهن قبل ان يسلمن ، ولو اشترى او امتلك جارية غير مسلمة هل يجوز له وطؤها؟ لا يجوز.