The United Nations' peacekeeping mission in Lebanon on Thursday called on authorities to investigate an attack in the country's south that left one of the force's members wounded.

Groups of young men in Lebanon's south -- a stronghold of the powerful Iran-backed Hezbollah group, where the UN force had previously suffered attacks -- blocked UNIFIL patrols twice since Wednesday, it said.

"A peacekeeper was hurt after a patrol was attacked by a group of young men in Taybeh" near the Israeli border late Wednesday, UNIFIL said in a statement, adding that "a vehicle was also damaged".

"We call on the Lebanese authorities to undertake a full and swift investigation, and for all perpetrators to be brought to justice," it said.

The UN force said such "attacks... are not only condemnable, but they are violations of (UN Security Council) Resolution 1701 and Lebanese law".

UNIFIL was set up in 1978 to monitor the withdrawal of Israeli forces after they invaded Lebanon in reprisal for a Palestinian attack.

It was bolstered in Resolution 1701 after Hezbollah and Israel fought a devastating war in 2006, and its roughly 10,000 peacekeepers are tasked with monitoring the ceasefire between the two sides.

Thursday's statement said peacekeepers' freedom of movement "is vital as we work to restore security and stability along the Blue Line", the frontier demarcated by the UN in 2000 after Israeli troops withdrew from southern Lebanon.

Lebanon's official National News Agency (NNA) said Wednesday that unidentified individuals stopped and attacked a patrol of the UN force's Indonesian contingent, breaking car windows and injuring one of the troops.

In a separate incident on Thursday, peacekeepers were "blocked for about four minutes as they travelled through" the border village of Kfar Kila, UNIFIL deputy spokeswoman Kandice Ardiel said.

The NNA said the Lebanese group of men forced a patrol of the French contingent to retreat after beating their vehicle with an iron stick.

Since October 8, the day after the Israel-Hamas conflict started, the frontier between Lebanon and Israel has seen escalating cross-border fire, mainly between the Israeli army and Hezbollah, which says it is acting in support of Hamas.

The UN force has itself been hit by fire, without causing any deaths among peacekeepers.

Last year, Private Sean Rooney, 23, was killed and three others were wounded after a UNIFIL convoy came under fire in south Lebanon.