An article titled “A Guide to the Perplexed about the
Permissibility of Killing Prisoners” says Islamic scholars present five
approaches drawn from various interpretations of the Quran:
1. A polytheist prisoner must be killed. No amnesty may be granted to him,
nor can he be ransomed.
2. All infidel polytheists and the People of the
Book (i.e., Jews and Christians) are to be killed. They may not be granted
amnesty, nor can they be ransomed.
3. Amnesty and ransom are the only two
ways to deal with (surviving) prisoners.
4. Amnesty and ransom are possible
only after the killing of a large number of prisoners.
5 .The Imam, or
someone acting on his behalf, can choose between killing, amnesty, ransom or
enslaving the prisoner. [Full