Lebanon’s Hezbollah used drones to strike Islamic State in Syria close to the border with Lebanon, a military media unit it runs said on Monday, their first public declaration that they had used such a weapon.

Hezbollah deployed the drones to hit Islamic State positions, bunkers and fortifications in the Western Qalamoun area near the border with Lebanon, achieving direct hits, the military media unit said.

An official in the military alliance fighting in support of Syrian President Bashar al-Assad told Reuters it was the first time Hezbollah had declared its use of the weapons.

Footage released by the media unit seemingly taken from a drone, showed two types of munition, one of them with a tail fin, dropping towards the ground and explosions as they hit.

Early on Saturday Hezbollah and the Syrian army began an operation against an Islamic State enclave straddling the border with Lebanon in Syria’s Western Qalamoun.

The Lebanese army began a separate but simultaneous operation against the same jihadist pocket from inside Lebanon.

Any joint operation between the Lebanese army on the one hand and the Syrian army on the other would be politically sensitive in Lebanon and could jeopardise the U.S. military aid the country receives.

Islamic State holds the last militant pocket on the border after a Hezbollah offensive last month that forced Nusra Front militants to leave for rebel-held Idlib province in Syria.

Northeastern Lebanon was the scene of one of the worst spillovers from Syria’s civil war in 2014 when Islamic State and Nusra Front militants attacked the town of Arsal.