Islamic State group fighters began evacuating a Syrian-Lebanese border region Monday under an unprecedented deal to end three years of jihadist presence there, Syrian state television and Hezbollah said.

The evacuation comes a week into a Lebanese army campaign against the group on the Lebanese side of the border, coinciding with a joint Syrian army and Hezbollah offensive on neighbouring Syrian territory.

Under the evacuation deal, several hundred jihadists and their families on both sides of the border are set to leave by bus for Deir Ezzor in eastern Syria, the country's only province still under IS control.

Early Monday evening, Hezbollah and Syrian state television said that "buses transporting IS fighters have left the (Syrian) region of Qara, in western Qalamun, and are heading for the town of Albu Kamal in Deir Ezzor".

Hezbollah said "hundreds of IS fighters" had left the border area of eastern Lebanon, but this was not confirmed by the Lebanese army.

"The objectives (of the operation) have been achieved," Hezbollah leader Hassan Nasrallah said in a speech broadcast live on the party's Al-Manar television channel.

"IS was expelled from Lebanese territory... the border was secured and the western Qalamun (on the Syrian side) was liberated" from the jihadists," he said.

Nasrallah said the battle had cost Hezbollah 11 fighters and the Syrian army seven soldiers. Lebanon's army has said it lost six soldiers.

Earlier, a Lebanese army source told AFP that no convoys would leave the area until DNA tests had been carried out on bodies found in the region at the weekend, believed to be the remains of eight Lebanese soldiers IS kidnapped in 2014.

The Lebanese army launched an offensive against IS in the mountainous Jurud Arsal and Jurud Ras Baalbek border regions on August 19.

It said Tuesday it had seized most of the territory formerly held by the jihadists.

At the same time, Hezbollah mounted a parallel offensive to dislodge IS from the Syrian side of the frontier.

The Lebanese army and Hezbollah announced a ceasefire on both sides of the border after reaching the evacuation deal over the weekend.

On Monday, dozens of Lebanese soldiers were seen manning positions on a string of hilltops in Jurud Ras Baalbek.

Most appeared relaxed, leaning on armoured personnel carriers and waving to journalists embedded with Lebanese troops.

Others manned vehicle-mounted heavy machineguns and looked out over the arid territory they had seized in the nine-day fight.

Smoke could be seen rising behind hilltops along the border.

"Daesh is burning its homes and bases before evacuating," a member of the special forces told AFP, using an Arabic acronym for IS.

Lebanese army General Fadi Daoud said the area had been secured, but that there was still a danger of mines laid by the jihadists.

"Daesh is done, but we may still find caves with bombs in them," he said.

"There are caves and small rooms in the area. If a soldier doesn't go into each room, clear it, and mark it as safe, then we can't say that we're done."

The war ravaging Syria has overflowed into Lebanon on several occasions.

IS has claimed several deadly bombings, clashed with the army and Hezbollah as well as winning a foothold in the mountainous east of the country.

Source: AFP