A Lebanese military source said the Israeli army had advanced to a depth of between five and nine kilometres (between three and 5.5 miles) inside Lebanese territory.

Israel's military has not given any geographical details on the furthest point to which its soldiers have advanced into Lebanon.

Israeli media reported that the military did not intend at this stage to push troops deeper than around 20 kilometres north of the border.

"At this stage, IDF soldiers have completed their deployment along the anti-tank missile defence line and continue to operate in the area in order to strengthen the forward defensive posture and remove threats to the residents and communities of northern Israel," a military statement said.

Defence Minister Israel Katz has said on several occasions in recent weeks that Israel intends to establish a "security zone" in southern Lebanon extending to the Litani river, which flows as much as 30 kilometres from the Israel-Lebanon border, in order to prevent rocket, drone or missile fire at northern Israeli communities.

- 'Preparing to boost its forces' -

The Lebanese military source told AFP on condition of anonymity that Israeli troops had advanced to a depth of around nine kilometres in the coastal area, reaching the town of Bayada.

In the central sector of the border, troops have reached five kilometres inside Lebanon, the source said.

In the east, "the Israeli army has reached a depth of seven kilometres", the source added, saying that Israeli troops also controlled the strategic town of Khiam.

"Huge explosions" have been heard from the area where Israeli troops have invaded, the source said.

Lebanon's army has withdrawn from these areas in order to avoid a confrontation.

A security source on the ground told AFP that Israeli troops are now stationed at points overlooking areas where they have advanced, including in Bayada.

A statement from Hezbollah said its fighters were clashing with Israeli troops on the eastern outskirts of Bint Jbeil, which saw fierce fighting in previous wars.

The Israeli daily Yediot Aharonot reported that the military was expected to present to the government "an operational plan for controlling the first line of (Lebanese) villages as a deep security zone up to the anti-tank line".

Israeli newspaper Haaretz, citing military sources, reported that the military was "preparing to boost its forces in southern Lebanon, but there are currently no plans to advance deeper into the country".

"The sources said the forces have reached what has been defined as the 'front line' outlined in the approved operational plans," Haaretz reported, adding that "this line includes southern villages located roughly 10 kilometres from the Litani river, an area under Israeli military control".

Haaretz also reported that the current deployment was aimed at preventing anti-tank missile fire on northern Israeli communities.

These anti-tank missiles have an estimated range of around 10 kilometres.