A U.N. peacekeeper armored vehicle is parked along the Lebanese-Israeli border in the southern Lebanese village of Marwaheen, Wednesday, July 12, 2023. AP
The incident comes amid tensions along the Israel-Lebanon border area, a stronghold of the Shia movement and the site of sporadic skirmishes.
"Three Hezbollah members were wounded by Israeli fire near the border," the source told AFP, requesting anonymity as they were not authorised to speak to the media.
Three other sources with knowledge of the incident also said Hezbollah members had been wounded. One said a sound grenade was fired and that three members were "lightly" hurt.
The Israeli army said in a statement that "a number of suspects approached the northern security fence with Lebanon and attempted to sabotage the security fence in the area".
"Soldiers immediately spotted the suspects and used means to distance them," the army said, adding that "the identity of the suspects is unknown."
An AFP correspondent said the incident took place near the village of Al-Bustan, where Lebanese army and peacekeepers were deployed.
The United Nations Interim Force in Lebanon (UNIFIL), which acts as a buffer between Lebanon and Israel, said it was "aware of disturbing reports about an incident along the Blue Line."
"The situation is extremely sensitive. We urge everyone to cease any action that may lead to escalation of any kind," it said in a statement.
Lebanon and Israel are technically at war. They fought a devastating war in 2006 after the group captured two Israeli soldiers.
The conflict killed 1,200 people in Lebanon, mostly civilians, and 160 Israelis, mostly soldiers.
Hezbollah chief Hassan Nasrallah said in a televised speech to mark the anniversary of the 2006 war that Wednesday's incident was "under investigation".
UNIFIL was set up in 1978 to monitor the withdrawal of Israeli forces after they invaded Lebanon in reprisal for a Palestinian attack. The UN mission was beefed up in response to the 2006 conflict, and operates in the south near the border.
Wednesday's incident comes less than a week after the Israeli army struck southern Lebanon following an anti-tank missile launch from its northern neighbour. The missile exploded in the border area between the two foes.
That same day, Hezbollah denounced Israel for building a concrete wall around the town of Ghajar.
The Blue Line cuts through Ghajar, formally placing its northern part in Lebanon and its southern part in the Israeli-occupied Syrian Golan Heights.
"This land will not be left to Israelis," Nasrallah said Wednesday.
"Through cooperation" between Hezbollah, the state and the Lebanese people, "we can get back our occupied land in Ghajar," he added.
The foreign ministry on Tuesday said Lebanon would file a complaint with the United Nations Security Council over Israel's "annexation" of the north of Ghajar.
Nasrallah also said Hezbollah had set up two tents recently in the Shebaa Farms -- one erected in a disputed area -- but that the Israelis had "not dared to take any steps on the ground" in response.
In June, Hezbollah said it shot down an Israeli drone that had flown into Lebanon's southern airspace.