An Israeli patrol "violated the Blue Line in the town of Aita al-Shaab, crossing it by about one metre," an army statement said, adding that a "Lebanese army patrol arrived at the location and forced the enemy to retreat behind the Blue Line".
The Blue Line refers to the UN-demarcated border between the enemy states after Israel withdrew from southern Lebanon in 2000.
A unit from the UN's Interim Force in Lebanon (UNIFIL) also arrived at the location and noted the breach, the statement added.
A Lebanese security source told Anadolu that Israeli forces were attempting to put up a barbed wire fence inside the Lebanese side of the border before the Lebanese army intervened and stopped them.
There was no immediate comment from Israel.
Last month, the Lebanese army called for the removal of a barbed wire fence erected by Israel in a disputed area in southern Lebanon
Lebanon highlights regular Israeli violations of its airspace, land and territorial waters. It has repeatedly urged the UN to intervene to stop these violations.