BEIRUT - A Lebanese army soldier opened fire on Israeli territory on Sunday evening, killing an Israeli soldier.
Lebanon's state National News Agency reported that Lebanese Armed Forces troops opened fire on Israeli soldiers near the Naqoura border crossing.
Hezbollah's Al-Manar television said that the Israeli troops had been attempting to cross into Lebanese territory.
However, the IDF said in a statement that "shots were fired at a civilian vehicle traveling along the Israel-Lebanon border," killing an Israeli soldier.
"The IDF has confirmed that the sniper is a member of the Lebanese Armed Forces."
The Israeli army later identified the soldier as Master Sergeant Shlomi Cohen, 31, from northern city Afula, according to AFP.
"The IDF has protested this outrageous breach of Israel’s sovereignty with UNIFIL and has heightened its state of preparedness along the border," spokesperson Peter Lerner said.
“We will not be lenient [in our response to] any attack against the state of Israel. We have the right to defend ourselves against those who attack Israel and its citizens.”
Israeli daily The Jerusalem Post reported that the IDF's initial assessment determined the Lebanese army sniper who started the shooting "was acting alone."
Meanwhile, UNIFIL spokesperson Andrea Tenenti said that “according to information we received, the incident took place on the Israeli side of the Blue Line” border demarcation with Lebanon.
He added that UNIFIL commander General Paolo Serra was in contact with top Israeli and Lebanese military chiefs to encourage restraint, the NNA reported.
The Lebanese soldier initially went missing after he opened fire on Israel, but returned to his barracks on Monday morning.
The sniper had been "hiding in an uninhabited wooded area following the incident," the National News Agency reported.
While there have been sporadic exchanges of fire with Syrians across the Israeli-occupied Golan Heights since the eruption of Syria's civil war, incidents on the Lebanese border have been rare since Israel's 2006 war against Lebanon's Hezbollah.
On Thursday, the Israeli army said that shots were fired across the frontier by what it called Lebanese "hunters." No casualties were reported.
In August, four Israeli soldiers on patrol were wounded in a blast 400 meters (yards) inside Lebanese territory, Lebanon's army and a UN peacekeeper in the border region said.
Hezbollah took credit for the explosion, its first such claim since the 2006 war.
Israel occupied large swathes of Lebanon from 1978 to 2000. The two countries are still officially in a state of war.
UNIFIL deployed at the border separating the two countries after a bloody war in 2006, that in just over a month killed some 1,200 Lebanese, mostly civilians, and 160 Israelis, mostly soldiers.