Four Israeli soldiers who were killed in southern Lebanon were likely killed in an accidental detonation of explosives as they demolished a Hezbollah tunnel laden with weapons, Israel's Army Radio reported Monday.

The Israeli military said four soldiers fell in combat, without providing further details. Army Radio said the incident happened Sunday and an initial review found the detonation set off secondary explosions, leading to the collapse of the tunnel while the soldiers were in it.

Israeli authorities did not blame the explosion on Hezbollah or say it was a violation of the Nov. 26 ceasefire agreement, though the two sides have accused each other of other infractions over the past two weeks.