UNIFIL said about 50 civilians swarmed its convoy in the southern village of Ayta Ash Sha'b and pelted it with stones.
"There were no injuries to the UNIFIL personnel, but the patrol vehicles sustained damages," the peacekeeping mission said in a statement Friday.
Maj. Gen. Paolo Serra, commander of the force, said he had serious concerns about the incident, noting it was a violation of its mandate for the freedom of movement.
UNIFIL has a mandate to secure the so-called Blue Line, a border area separating Israel from Lebanon. Serra said Thursday during talks with Lebanese Prime Minister Tammam Salam the border area was "relatively stable."
Salam ended a 10-month stalemate this week by forming a government of eight ministers each from the March 8 political slate, which includes lawmakers from Hezbollah, March 14, a Western-backed group, and independents.
Lebanon's national security is under threat from civil war in neighboring Syria.