The Lebanese army opened fire at two of three Israeli drones that crossed the border in south Lebanon on Wednesday.
Troops fired shots from M16 assault rifles, Reuters reported.
The President of Lebanon, Michel Aoun, said on Monday his country had a right to defend itself, after an Israeli drone crashed in Beirut suburbs on Sunday.
The incident happened on Wednesday night over the village of Odeisseh, near Marjayoun, close to the border with Israel, the National News Agency reported.
The Lebanese army said the three drones returned to Israel after coming under fire.
“Gunfire was heard from Lebanese territory towards the area where Israeli drones were flying," the army said. "The drones ended their mission and no damage was caused."
The Israel Defence Forces mainly confirmed the Lebanese Armed Forces’ claims.
"A Lebanese army position in the district of Al Adeesa in south Lebanon saw a drone and they fired at it, and it returned" to Israel, a military source told AFP.
"The fire comes in the context of previous instructions that any Israeli movement inside Lebanese territory should immediately be fired at."
The Lebanese army said it shot at the first drone after "it violated Lebanese airspace".
A second drone flew over the nearby area of Kafr Kalla before returning to Israeli airspace, while the army also shot at a third, apparently also in Al Adeesa, the Lebanese army told the National News Agency.
The incident comes after the biggest escalation between Israel and the Iran-backed Lebanese militia Hezbollah in years, after strikes in Syria and two Israeli drones crashing in southern Beirut on Saturday.
The agency reported a fourth drone in the Lebanese border area of Marwaheen, dozens of kilometres to the south along the border.
The Israeli army said its aircraft returned undamaged.
The two countries technically remain at war after fighting a one-month conflict in 2006.
Lebanese officials have pledged to protect the country's sovereignty in response to Israeli incursions.
Hezbollah has ruled out a wider war with Israel but says it will carry out a surprise attack in retaliation for the weekend's attacks.
Naim Qassem, deputy secretary general of Hezbollah, said the militant group would not be "intimidated by threats of war in order not to retaliate".
"There was an aggression and we said we will retaliate and this is what will happen," Qassem told Russia Today on Tuesday.
"We want the strike to be surprising and therefore it is not in our interest to reveal more details."
The UN Security Council is expected to meet on Thursday to review the peacekeeping mandate for the UN Interim Force in Lebanon on the Israeli-Lebanese border.
The US has been pushing for the force on the border to prevent weapons smuggling by Hezbollah.
The US administration has also, under pressure from Congress, been reviewing its aid for the Lebanese army, which is about $70 million (Dh257m) a year.