"We have to prepare for all scenarios of neutralizing the tunnels," Israel Defense Forces spokesman, Brig. Gen. Ronen Manelis, told reporters. "Some of [the scenarios] will not be in our territory and this is something we are preparing for."
The Israel Defense Force announced the discovery of the tunnels on Tuesday morning, saying it has started destroying them, dubbing the campaign Operation Northern Shield.
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Israel has warned Lebanon and UNIFIL, the United Nations peacekeeping mission in South Lebanon, that anyone who approaches the area puts himself in danger, Manelis said.
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He added that the tunnel revealed on Tuesday was dug from a private home in Kafr Kila in southern Lebanon. It took two years to build, he said, and stretches some 200 meters – 40 of which are inside Israeli territory.
Contrary to the Gaza tunnels, Manelis added, these tunnels have air conditioning, lighting and are tall enough for people to walk upright.
After the 2014 Gaza war, Manelis said, Israel "understood that there is an underground threat against Israel that needs to be removed. Two teams are created: One in the south, which has so far exposed some 17 tunnels, and another [team] on the Northern Command, which operated under the assumption that if there are tunnels in the south, it is likely there are [tunnels] in the north."
Operation Northern Shield, added Manelis, will last several weeks: "Some actions will be more precise and some less. At this point we are operating within Israeli territory to seize the tunnels… in the future, these tunnels may be destroyed from other locations."
Manelis said that "The decision to keep the operation a secret was made in order to surprise Hezbollah," adding that the timing of the launch was determined after all of the intelligence and technological conditions were right. "This operation wasn't approved last night," he said.
Prime Minister Benjamin Netanyahu said Tuesday that there had already been "operational successes" in the operation.
"Whoever tries to harm the State of Israel will pay a heavy price," Netanyahu said in a statement, adding that Israel "is operating divisively and responsibly on all fronts simultaneously. We will continue with further actions – public and clandestine – in order to safeguard the security of Israel."
Netanyahu held a security briefing with IDF Chief of Staff Lt. Gen. Gadi Eisenkot, the head of the National Security Council and other defense officials.
The security cabinet has convened to discuss further developments in the operation.
Israeli envoy to the United Nations Danny Danon called upon the UN Security Council to convene following the discovery of the attack tunnels.
"Hezbollah continues to act under the funding, guidance and sponsorship of Iran. The Security Council clearly told Hezbollah it cannot arm itself and continue its terrorist activities against Israel," Danon said outside the council on Tuesday. "It's clear now that Hezbollah flouts the Security Council and is aggresively violating resolution 1701."
Danon added that Israel expects the international community and the Security Council "to condemn this activity by Hezbollah and demand the Lebanese government implement the Security Council's decisions."