Okay, let's pretend we living in the world of Equestria with pinky ponies all around and Geneva Convention really works and stopping russians from torture civilians and cut their dicks in Bakhmut. Also, we need to pretend that Hamas joined as Geneva Convention member. So, how Geneva Conventions threat a man that claimed to be civilian but actively participates in combat?

An exception to this rule is the levée en masse, whereby the inhabitants of a country which has not yet been occupied, on the approach of the enemy, spontaneously take up arms to resist the invading troops without having time to form themselves into an armed force. Such persons are considered combatants if they carry arms openly and respect the laws and customs of war (see commentary to Rule 106).

Also, let's see what Hamas should do about hostages:

The taking of hostages is prohibited.

Oh boy.

Jokes aside, again, as I said: everyone who wanted to leave is already flee. Not like you see how your neighborhood stoking up weapons and rockets to strike nearby country and be like "I'm sure that just to made fireworks!". Do you think after russia invaded Ukraine, everyone just stayed at home and just ignored massacre on the streets? Nope sir, the one who was against that invasion just flee from occupied land, only one who couldn't find strength to leave own home and the people, who praised invasion stayed that day. Well, both groups was tortured anyway, but that beside the point. My point is, there almost no "civilians" left. There combatans and some that described by Geneva Conventions as "non combatants". But no civilians. Prove me wrong tho.