Of course, this is a problem in almost any army--there are soldiers who take advantage of warfare for this reason. Armies that punish it severely, as most do, still have a problem with it. Armies that turn a blind eye, or actively encourage it, will have a huge problem.
Still, I found it interesting that the Wikipedia article about the Beslan Massacre says:
The lack of food and water took its toll on the young children, many of whom were forced to stand for long periods in the hot, tightly-packed gym. Many children took off their clothing because of the sweltering heat within the gymnasium, which led to rumors of sexual impropriety, though the hostages later explained it was merely due to the stifling heat and being denied any water.Yet the two sources that this paragraph (here and here) gives for this claim says nothing that indicates that the claims of rape were incorrect. I find myself troubled by how many books and articles refer to this claim, which seems unfortunately quite plausible--and yet I can't find any immediate newspaper accounts that refer to it. Can you help me?