BEIRUT (REUTERS) - Lebanese Hezbollah launched attacks against radical Sunni militants on Monday (July 24) as part of an offensive to drive them from their last foothold along the Syria-Lebanon border, a military media unit of the group said.

Forces of the Iranian-backed Shi'ite group advanced from several directions against militants in the Wadi al-Kheil area of Juroud Arsal, a barren mountainous border zone which has served as a base for jihadists.

The offensive, launched on Friday by Hezbollah and the Syrian army, has so far focused on militants from Al-Qaeda's former Syria branch, previously called the Nusra Front.

The Hezbollah media unit has reported rapid advances against Nusra fighters. The next target will be territory held by Islamic State in Iraq and Syria (ISIS) militants, local media have reported.

The Syrian army and Hezbollah recaptured the area around the town of Fleita on the Syrian side of the border on Sunday, Syrian state news agency Sana said.

The offensive has so far killed 19 Hezbollah fighters and more than 130 Sunni militants, according to a security source.

Hezbollah has played a critical part in previous campaigns against Sunni insurgents along Lebanon's border, part of its wider role backing President Bashar al-Assad in the Syrian war.

Hezbollah's role has drawn criticism from its Lebanese political opponents, including Prime Minister Saad al-Hariri, who is a Sunni.