This may be tough to understand but there's a ton of still completely-intact, dense urban environment in between the border and the school in your scenario. So on your way to the school, you can be ambushed.

Or hey, maybe thinking strategically even a little bit, maybe the school, or the road, or any of the surroundings are booby-trapped! Maybe they've planted IEDs or mines on the path there!

It's very far fetched, I know. Humans haven't been waging war for forever, there isn't a giant history to pull from.

"The terrorists are using schools as shields though!"

"Oh damn that's a genius strategy. Better just give up every military advantage I have and send in my soldiers to be ambushed."

I don't know if you noticed but it's been more than 24 hours since they said that and they're still letting them evacuate. Time to retire that talking point.

There are food banks, don't steal.