I'm reminded of an episode of Saga of Tanya the Evil where a 'guerilla military unit' had 'taken over a captured city'. The progag's military unit had to go 'clear the city'. Their military commanders had given clear orders that all hostile forces were enemy soldiers who must be killed. They started by issuing a demand to release the hostages and allow them to exit the war zone. One of the few who didn't want to fight was shot while trying to escape. From that point it predictably went in a very bad direction.

As far as I'm aware, the citizens of Israel are free to leave that country* (free to enter another country is another issue, but they're also free to move about). It's terrorism and illegal military action to knowingly fire upon civilians. I agree with that for all sides of a conflict. The issue with the other side(s) in this conflict is that they do not present as a clearly identified military force. IMO the most proper solution is the same as evaporatively purifying water. Issue sufficient (<< heavy lifting here) warnings for civilians to leave an area, with an area for them to move to. Then any who remain in the military action area are combatants. Probably just like in the anime episode that showcases this circumstance. (war is hell, that's one of the hells.)