The UN Interim Force in Lebanon (UNIFIL) said on Wednesday that direct fire from the Israeli army had hit the perimeter of one of its peacekeeping positions in south Lebanon.
In a statement, UNIFIL said the incident on Tuesday was the first of its kind since Israel and Iran-backed Lebanese group Hezbollah agreed to a ceasefire last November.
There was no immediate comment from the Israeli army on the incident, in which UNIFIL said one of its bases in the village of Kfar Shouba in southern Lebanon was hit.
"In recent days, UNIFIL has also observed other aggressive behavior by the Israeli military towards peacekeepers performing operational activities in accordance with Security Council Resolution 1701," it said, referring to a UN resolution originally adopted in 2006 to end hostilities between Israel and Hezbollah.
Tuesday's incident occurred near the Blue Line, a UN-mapped demarcation separating Lebanon from Israel and the Israeli-occupied Golan Heights.
Any unauthorized crossing of the Blue Line by land or by air from any side constitutes a violation of Security Council Resolution 1701.
UNIFIL cited other alleged incidents it blamed on the Israeli army, including being targeted by lasers while it was performing a patrol with the Lebanese army in the southern border town of Maroun al-Ras on Tuesday.
Israel has continued to occasionally strike areas in south Lebanon, saying that it was targeting Hezbollah infrastructure. It has also struck the Hezbollah-controlled southern suburbs of Beirut several times.
The ceasefire terms require that neither Hezbollah nor any other armed group have weapons in areas near the border south of the Litani River, which flows into the Mediterranean some 20 km (12 miles) north of the Israeli border.
They require Israel to withdraw troops from the south and that the Lebanese army deploy into the border region.
Lebanon and Israel have accused each other of failing to fully implement the deal. Israel still occupies five hilltop positions in the south. Rockets have been fired from Lebanon towards Israel twice, though Hezbollah denied any role.
Israel killed thousands of Hezbollah fighters in the war, destroyed much of its arsenal and eliminated its top leaders, including Hassan Nasrallah.
The war spiraled after Hezbollah opened fire at the beginning of the Gaza war, declaring solidarity with its Palestinian ally Hamas.
