The Israeli army announced on Sunday that it has discovered a fourth Hezbollah tunnel running from Lebanon into Israeli territory.
The latest tunnel crossing into northern Israel was exposed at the weekend, the army said in a statement.
As with the other tunnels, soldiers placed explosives in it to keep out militants from the Lebanese side, it said.
The military refused to give the exact location, stressing the tunnel did not "pose an imminent threat".
Earlier this month, Israel launched operation Northern Shield to expose and destroy Hezbollah tunnels that the group had dug for use in future conflict.
Israel fought a devastating war against Hezbollah in 2006 that was halted by a UN-brokered truce.
"The Lebanese government is held accountable for the attack tunnels dug from Lebanese territory," the military statement said Sunday.
"This is another blatant breach of UN Resolution 1701 and of Israeli sovereignty," it added, referring to the resolution ending the 2006 war.
Hezbollah, which used such tunnels inside Lebanon in the 2006 war, has yet to comment on the Israeli operation.
On Wednesday, Prime Minister Benjamin Netanyahu said the UN peacekeeping force in southern Lebanon, UNIFIL, and international community should do more to curb Hezbollah's "acts of aggression against Israel".
UNIFIL has verified the existence of two of the tunnels Israel has exposed so far.
