JERUSALEM -- Hezbollah militants on Sunday fired a barrage of anti-tank missiles into Israel, prompting a reprisal of heavy Israeli artillery fire in a rare burst of fighting between the bitter enemies.
Although the shooting quickly subsided without casualties on either side, the situation remained volatile. The bitter enemies, which fought a monthlong war in 2006, have indicated they do not want to go to war but appeared on a collision course in recent days after a pair of Israeli strikes against Hezbollah. The militant group vowed it would retaliate.
Lebanese Prime Minister Saad Hariri held telephone calls with U.S. Secretary of State Mike Pompeo as well as an adviser to French President Emmanuel Macron urging the international community to calm the situation. The U.N. peacekeeping mission in southern Lebanon, known as UNIFIL, said it was in contact with all sides and urged restraint.
U.N. spokesman Andrea Tenenti said later that "calm has returned in the area" and the U.N. peacekeeping force is maintaining its presence on the ground together with the Lebanese army.
By nightfall, the fighting appeared to have halted. But Israeli officials said troops remained on high alert.
"We are consulting about the next steps," Prime Minister Benjamin Netanyahu said. "I have ordered that we be prepared for any scenario. We will decide on the next steps pending developments."
Hezbollah's deputy leader, Naim Kassem, said Sunday night that the group was committed to retaliating whenever it comes under attack. "Hezbollah wants to preserve deterrence and the rules of engagement in order to prevent something worse from happening," he said.
Israel considers Iran to be its greatest enemy, and Iran-backed Hezbollah to be its most immediate military threat. Hezbollah has a battle-tested army that has been fighting alongside the forces of Syrian President Bashar Assad in Syria's civil war, and it is believed to possess an arsenal of some 130,000 missiles and rockets.
Throughout the Syrian war, Israel has acknowledged carrying out scores of airstrikes in Syria aimed at preventing alleged Iranian arms transfers to Hezbollah. But in recent weeks, Israel is believed to have widened its campaign and struck Iranian or Hezbollah targets in Iraq and Lebanon as well.
Last weekend, Israeli warplanes thwarted what Israel said was an attempt by Iran to launch a squad of attack drones based in Syria. Two Hezbollah operatives were killed in the strike, and Hezbollah has sworn it will not let the killings go without a reply.
Hezbollah also promised to respond to what it says was an Israeli drone strike in Beirut last week. Israeli media have said the strike destroyed a "planetary mixer," a sophisticated piece of equipment needed to manufacture guided missiles.
"The Islamic Resistance carried out the secretary general's promise to retaliate for the two aggressions," Hezbollah's Al-Manar TV presenter said Sunday, referring to the recent Israeli strikes.
The Israeli army believes that Iran and Hezbollah are racing to establish missile-production factories in Lebanon -- a claim that Hezbollah denies.
In Sunday's fighting, Israel said Hezbollah fired two or three anti-tank missiles at an Israeli military base along the border. The army said the base, as well as a military ambulance, suffered damage.
The military said it responded with about 100 artillery shells, as well as helicopter fire, toward the areas from where the missiles had been launched.
Israel has bolstered its forces along the Lebanese border, and Lt. Col. Jonathan Conricus, a military spokesman, said Sunday's fighting was one of the "scenarios" Israel had anticipated. He said that while the current round of fighting appeared to be over, the deeper "strategic" situation remained the same and that forces remained on high alert.
In Lebanon, the Israeli shelling was concentrated on areas close to the border near the villages of Maroun el-Ras and Yaroun, triggering some fires.
Hezbollah said the unit that carried out the attack on Israel was named after two operatives who were killed in the Israeli airstrike on Syria on Aug. 24.
Earlier Sunday, the Lebanese army had claimed an Israeli drone violated the country's airspace and dropped flammable material on fields, triggering a fire that was extinguished shortly afterward by residents.
Israel and Hezbollah fought a bruising, monthlong war in 2006 that ended in a stalemate. Despite their deep hostility, they have largely refrained from direct fighting for the past 13 years.
In January 2015, Israel launched an airstrike against a Hezbollah convoy in the Syrian Golan Heights, killing at least six militants and an Iranian general. Later that month Hezbollah retaliated by firing anti-tank missiles at an Israeli military convoy, killing two Israeli soldiers.
Over the past year, Israel uncovered and destroyed what it said was a network of cross-border Hezbollah attack tunnels.
During Sunday's fighting, the military encouraged residents near the northern border with Lebanon to stay indoors and ordered public bomb shelters to open. By late Sunday, it lifted most restrictions, saying only that farmers should stay away from the immediate border area.
