Hezbollah attacked Wednesday the Metula post with a suicide drone.
It said it acted "in response to the Israeli aggression against the villages of the south and the homes of civilians."
Israeli artillery meanwhile shelled the outskirts of al-Fardees and Rashaya al-Fokhar and warplanes raided the southern border town of Yaroun.
Hezbollah had carried out several attacks on Israeli military positions on the border on Tuesday, in response to a strike on a house in Houla that killed a man, his wife and their son. Hezbollah announced the deaths of the father, Hassan Hussein, and his 25-year-old son, Ali Hussein, "on the road to Jerusalem" -- the phrase used for Hezbollah fighters killed by Israel.
Hezbollah and Israel have traded deadly cross-border fire on a near-daily basis since the Israeli war on Gaza broke out in October.
The fighting has killed at least 302 people in Lebanon, most of them Hezbollah fighters but also including at least 50 civilians, according to an AFP tally.
In Israel, at least 10 soldiers and seven civilians have been killed.