The Lebanese troops were dismantling the Iran-backed group's weapons facility near the Israeli border when the explosion occurred. Beirut is under pressure to disarm Hezbollah under a ceasefire deal signed in November.

Hezbollah said on Wednesday the Lebanese government was committing a "grave sin" by tasking the army with establishing a state monopoly on arms, sharpening a national divide over calls for the Shi'ite Muslim group to disarm.