I think we have in fact pretty strong reporting that at least 2 children were killed, and while the explosions and payload were nowhere nearly as devastating as a grenade, they were still much bigger than a firework mortar (which themselves have killed children).

I think a stronger argument is that in the aggregate, the devices overwhelmingly targeted combatants.

The 2 kids killed picked up their dad's pager.

There are videos where the surrounding people were hurt by the pagers, so, what's the explaination for that?

I'm sure those exist --- it has never been my claim there there were zero or even just few civilian casualties --- but the videos I've seen had people standing next to the person carrying the pager walking away, startled but apparently unharmed. The explosions were quite small (I quantified them downthread from what Reuters reported).

Please provide links to these videos because every video I saw showed only the person holding the pager getting hurt. They only had 6 grams of explosives.