They are, but we hear about it less. Our media doesn't give a shit about poor brown and black children in other countries getting slaughtered, because there is no political action associated with such tragedy. Media kinda care when the biggest attack on a school in history happens, but only kinda.
Everyone remembers Columbine.
Few in the US remember
Beslan.
There does seem to be VASTLY more terrorism aimed at schools outside the US. Do we see more psychopathy aimed at schools in the US? I'm not sure.