A projectile fired from Lebanon hit an open area in Israel on Monday and Israeli artillery targeted an area where the attack was launched, the Israeli military said.
The rare flareup on the Israeli-Lebanese border followed clashes over the past two weeks between Palestinians and Israeli police at Al-Aqsa mosque compound in Jerusalem that have stoked Arab anger and international concern.
Small Palestinian factions in Lebanon have fired sporadically on Israel in the past.
On Twitter, the Israeli military said no sirens were sounded and no alert was declared in northern Israel when the projectile, which it did not identify in its posting, struck.