An AFP correspondent reported Israeli artillery bombardment on the hills of Kfarchouba in the Shebaa Farms area near the Israeli position of Roueysaat al-Alam, and reported plumes of smoke rising above the area.

Lebanon and Israel are still technically at war and UNIFIL usually patrols the border between the two.

"Major General (Stefano) Del Col has been in contact with both parties to assess the situation and decrease tension while urging maximum restraint," UNIFIL spokesman Andrea Tenenti said.

"The firing has now stopped," he added.

Shiite movement Hezbollah, which has a large presence in the area, issued no immediate statement on Monday's incident.

But its Al-Manar television channel said calm had returned to the area.

Iran-backed Hezbollah is a key political player in Lebanon, despite it being blacklisted as a "terrorist" group by the United States. Its fighters support the Damascus regime in the civil war in neighbouring Syria.

Monday's border exchange comes a week after an Israeli missile attack hit positions of Syrian regime forces and their allies south of Damascus on July 20, killing five. Hezbollah said one of its own died in the raid.

Hezbollah number two Naim Qasim said in a televised interview on Sunday that "if the Israelis decide to launch a war, we will confront it and we will respond."

"What happened in Syria is an aggression, which led to the death of Ali Kamil Mohsen," he said of last weeks' strikes.

Israel has launched hundreds of strikes in Syria since the start of the country's civil war in 2011.

Israel and Hezbollah last fought a 33-day war in Lebanon in the summer of 2006.