I am pretty sure that only leaders of states can commit war crimes. Hamas is a legitimate leadership in Gaza and is therefore chargeable with war crimes for firing rockets. You would have to prove that 'acts of terror' commited by Palestinian groups came from some legitimate authority. As Palestine is not a state... see where that is going? Ironically enough, Israel is a state and the actions of the IDF amd the policy of settlement do come from a legitimate government authority. So, with palestine not a state and Israel being a state, Israeli's can be idicted for war crimes whereas the PA cannot.
2 Turkish security personnel killed, 24 wounded by Kurdish suicide bomb in eastern Turkey (Reuters)
from the article: Israel freezes UNESCO funding after Palestinian membership