Is Israeli treatment of Palestinian prisoners in accordance with the international law?

Its been stated that at present Israel are holding over 9,000 prisoners many young children imprisoned for throwing stones at the IDF This must be against human rights . Do Israel, as occupiers, have the right to imprison anyone, not to mention the 1.5 million imprisoned in the Gaza strip As for Gilad Shalit he is just a prisoner of war and when a satisfactory peace deal is agreed by both parties he will be released . He will be a major factor when they finally sit down and try to arrange some kind of deal