Hezbollah has warned Israel against attacking any Palestinian officials in Lebanon.
The comments by Hassan Nasrallah, the leader of the Iran-backed militants, come after Israel’s bombardment of the Gaza Strip last week.
Dozens of people were killed, including at least 15 children, as Israeli forces tried to assassinate senior militants belonging to the Palestinian Islamic Jihad group.
Israeli Defence Minister Benny Gantz has hinted at striking Islamic Jihad figures in "restaurants and hotels in Tehran, Syria and Lebanon".
Mr Nasrallah hit back on Tuesday, saying: "We tell the enemy that any attack on any human being in Lebanon will not go unpunished or unanswered."
The Hezbollah leader's remarks also follow the shooting of an official from Fatah, the movement of Palestinian President Mahmoud Abbas, in Lebanon’s largest Palestinian refugee camp.
Saeed Alaeddine, who was reportedly shot dead while praying at a friend's house in the Ain Al Helweh camp near the southern city of Saida, was in charge of liaising between Fatah and the Lebanese security forces.
The circumstances of his death and the identity of the gunman are unknown, with an army source saying an investigation was under way.
Israel and Hezbollah are arch foes and fought a month-long war in 2006. Tensions have been on the rise in recent months amid a maritime dispute in the Eastern Mediterranean.
Mr Nasrallah, who made a speech on Tuesday to mark Ashura, the commemoration of the killing of the Prophet Mohammed's grandson, Hussein, renewed his threats over the sea dispute.
“Don’t make mistakes with Lebanon nor with the people of Lebanon,” Mr Nasrallah said. “Any arm that tries to reach for any of this [Lebanese] wealth will be cut off.”
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US energy envoy Amos Hochstein, who is mediating indirect negotiations, was in Beirut last week and suggested that the prospects of reaching a deal were improving.
In June, tensions escalated when Israel moved a vessel close to the Karish gasfield, which Lebanon partially claims. The vessel is expected to go into operation by September.
Mr Nasrallah has previously suggested that war would break out if Israel begins extracting gas before a deal has been reached.
“We will not tolerate the idea that our wealth be stolen,” he said. Mr Nasrallah said Lebanon “should be ready for all possibilities".
Lebanon is awaiting a response to an offer on the maritime dispute it submitted to Mr Hochstein last month.
"We are waiting for a response to the demands of the Lebanese state, and we will respond accordingly, but I tell you ... we must be ready and prepared for all possibilities," Mr Nasrallah said.
"We will go all the way, so no one should try us."
Last month, Israel downed three unarmed drones that Hezbollah sent to Karish.