The Israeli military said its artillery shelled southern Lebanon early Tuesday after two rockets were fired from Lebanon into Israeli territory.
Israel's army said in a statement that aerial defenses intercepted one of the rockets, and the second fell in an open area. No injuries or damage were reported.
The U.N. peacekeeping force in Lebanon, known as UNIFIL, said its radar detected rockets fired from southern Lebanon toward Israel just before 4 a.m. Subsequently, Israeli artillery fired toward Lebanon, the U.N. force said.
Lebanon's army said Israel fired 12 artillery shells at the Wadi Hammoul area, causing no damage or casualties. The army said its units there had found three launching pads for Grad rockets.
The rocket fire from Lebanon was the first such cross-border incident since May, when Palestinian fighters launched rockets at Israel during the 11-day war between Israel and Hamas in the Gaza Strip.
Visiting a town near the Lebanese border, Israeli Prime Minister Naftali Bennett said that "anyone who tries to harm us will pay a painful price in return."
Israeli Defense Minister Benny Gantz said in a statement that Lebanon was responsible for the overnight rocket fire and that "Israel will act against any threat to its sovereignty and its citizens."
"We will not allow the social, political and economic crisis in Lebanon to turn into a security threat to Israel," Gantz said. Lebanon has struggled with an unprecedented crisis, including an economic meltdown that has raised concerns of a surge in militancy there.
UNIFIL said it was in contact with military officials in Lebanon and Israel to "urge maximum restraint" to avoid further escalation. Both the peacekeepers and the Lebanese army increased security in the area and launched an investigation, the mission said.
The incident along Lebanon-Israel frontier came hours after a Syrian military official said Israel carried out airstrikes near the northern Syrian city of Aleppo. The Syrian state news agency said air defenses intercepted most of the missiles in the attack.
The Britain-based Syrian Observatory for Human Rights, a war monitor that has activists on the ground in Syria, said the Israeli strikes targeted weapons depots belonging to Iranian-backed militant groups operating in the region.
Israel has carried out scores of airstrikes in Syria in recent years targeting Iranian forces there, and attacking what Israel says are weapons shipments bound for the Iranian-backed militant group Hezbollah in Lebanon.
The Israeli military rarely comments on these strikes.
