Article 52: General Protection of Civilian Objects
1. Civilian objects shall not be the object of attack or of reprisals. Civilian objects are all objects which are not military objectives as defined in paragraph 2.
2. Attacks shall be limited strictly to military objectives. In so far as objects are concerned, military objectives are limited to those objects which by their nature, location, purpose or use make an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage.
3. In case of doubt whether an object which is normally dedicated to civilian purposes, such as a place of worship, a house or other dwelling or a school, is being used to make an effective contribution to military action, it shall be presumed not to be so used. Article 53 Protection of cultural objects and of places of worship without prejudice to the provisions of the Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict of 14 May 1954, and of other relevant international instruments, it is prohibited:
a. to commit any acts of hostility directed against the historic monuments, works of art or places of worship which constitute the cultural or spiritual heritage of peoples;
Now see this video of what is prima facie a direct violation of this protocol: in short, a War Crime, being the deliberate attack on a Masjid, a Mosque.
Except.... there are "secondaries". Secondary explosions as a consequence of the original attack. Explosions that do the majority of the damage to the building. Explosions proving beyond any doubt that the building was being used for military purposes, storing weaponry being used for indiscriminate attacks against civilians - a war crime in itself.
The Geneva Protocol doesn't end there, you see. The rest of the protocol states:
b. to use such objects in support of the military effort;The indiscriminate attacks themselves are another war crime, as are attempts to use "human shields". That's covered in the preceding article, Article 51.
c. to make such objects the object of reprisals.
The military actions in Gaza by the Israeli Defence Forces are being conducted with Lawyers looking over the soldiers' shoulders. Their actions have been scrupulously careful to comply with the letter and the spirit of the Law of Armed Conflict.
Except nothing is certain in war. "Blue on Blues" - "Friendly Fire Incidents" where armies end up killing their own people happen, no matter how careful they are. Civilians in the area of operations get killed the same way. One can only minimise the slaughter of the innocent, not prevent it. This becomes doubly hard when the enemy views its own population as instruments of propaganda, deliberately putting them at maximum risk, and violating the Laws of War at every turn by doing so.