Hizballah seizes strategic valley from militants at Syria-Lebanon border
The Shia Muslim Hizballah said it had advanced from several directions in the Wadi al-Kheil valley in Juroud Arsal, a mountainous border zone that has served as a base for militants linked to al-Qaeda and the Islamic State group.
Several thousand Syrian refugees also occupy camps east of Arsal.
The advance gave Hizballah control over what had been "the most important base for Nusra Front" in the area, Hizballah's military media unit claimed in a statement.
The offensive, launched on Friday by Hizballah and the Syrian regime's army, has so far focused on militants from al-Qaeda's former Syria branch, previously called the Nusra Front.
Hizballah has reported rapid advances against Nusra fighters. The next target will be territory held by Islamic State militants, local media have reported.
The offensive has so far killed 19 Hizballah combatants and more than 130 Sunni militants, according to a security source.
A Lebanese mediator was also killed in the crossfire on Saturday.
Hizballah, backed by Iran, have been instrumental to the Syrian regime's battle against rebels and jihadists along Lebanon's border, part of its wider role backing President Bashar al-Assad in Syria's six-year-old civil war.
Hizballah's role has been criticised by its Lebanese political opponents, including Sunni Prime Minister Saad al-Hariri who is vurrently visiting the US for a meeting with Donald Trump\. On Monday, his Future Movement stressed Hizballah's offensive does not legitimise its involvement in the Syrian war.
Carefuly not to be seen as supporting Hizballah and the Syrian regime, the Lebanese army has remained officially neutral in the offensive, but has stepped up its defensive measures along the border.