JERUSALEM – Israel was drawn into the fighting in neighboring Syria for the first time Sunday, firing warning shots across the border after an errant mortar shell landed near an Israeli military installation in the Golan Heights.

While Israel appeared eager to calm the situation, its response was a potent reminder of how easily the Syrian civil war – already spilling across borders with Turkey, Lebanon and Jordan – could explode into a wider regional conflagration.

Israeli officials threatened even tougher retaliation if attacks persist.