"The massacre on Shabbat constitutes the crossing of all red lines by Hezbollah," the Foreign Ministry said on Sunday.
"This is not an army fighting another army. Rather, it is a terrorist organization that deliberately fires at civilians. Israel will exercise its right and duty to act in self-defense and respond to the massacre."
The attack by Hezbollah on a Druze town in the North resulted in 12 children being killed and many wounded.