Meanwhile the IDF have attacked an UNIFIL installation in Lebanon.
The UN peacekeeping force in southern Lebanon says Israeli tanks forced their way into one of its positions early on Sunday morning.
In a statement, the UN Interim Force in Lebanon (Unifil) said two Israel Defense Forces (IDF) tanks destroyed the main gate of a post in Ramyah, near the Israeli border, and "forcibly entered the position" to request it turn out its lights.
About two hours later, it said rounds were fired nearby that saw smoke enter the camp, causing 15 peacekeepers to suffer skin irritations and gastrointestinal reactions.
The IDF offered a different version of events, saying it had encroached on a Unifil position to evacuate soldiers who had been wounded by an anti-tank missile.
It said two soldiers had been "seriously injured" in the attack, with others suffering lesser degrees of injury.
"For the sake of evacuating the wounded, two tanks drove backwards, in a place where they could not advance otherwise in light of the threat of shooting, a few metres towards the Unifil position," the IDF said.
It added that during the incident, a smoke screen was fired to aid the evacuation - and that it had "maintained continuous contact" with Unifil, stressing there was "no threat to the Unifil force from IDF activities".
UN secretary general António Guterres warned any attacks on peacekeepers "may constitute a war crime", adding that "Unifil personnel and its premises must never be targeted".
"Attacks against peacekeepers are in breach of international law, including international humanitarian law," Mr Guterres said, according to a statement from his spokesman.
The incident is the latest in a growing number of encounters between Unifil and Israeli forces.
Israel has repeatedly urged the peacekeeping force to withdraw from areas of southern Lebanon where fighting was taking place, after it began a ground incursion on 30 September targeting the armed group Hezbollah.
Israel's Prime Minister Benjamin Netanyahu told Unifil to "immediately" get its troops "out of harm's way" in a video statement issued by his office on Sunday, claiming that their presence in the region made them "hostages of Hezbollah".
Unifil has so far refused these requests.
It comes as PM Netanyahu demands the peacekeeping force leave the area.
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3 days before that incident Joe Biden urged Israel to stop attacking UNIFIL peacekeepers in Lebanon.
Israel has acknowledged that shots fired by its military injured two UN troops in southern Lebanon on Friday.
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