(Bloomberg) -- United Nations peacekeepers stationed in south Lebanon said they visited the site of an underground tunnel that Israel said the Iran-backed Hezbollah group had dug to infiltrate the Jewish state.

The head of the UN Interim Force in Lebanon, Major General Stefano Del Col, and a technical team inspected the location of the tunnel discovered by Israel close to the Blue Line that was set up when Israeli forces withdrew from the country in 2000. UNIFIL said in a statement that it’s pursuing “urgent follow-up action,” and will give its preliminary findings to Lebanese authorities.

The announcement follows an Israelioperation, dubbed Northern Shield, to destroy what it said were tunnels dug by Hezbollah that reached its territory. While Israel has acted against cross-border tunnels from the Hamas-ruled Gaza Strip for years, Tuesday’s operation was its first open acknowledgment of Hezbollah tunnels from the north.

Lebanon’s foreign ministry said Friday it will lodge a complaint with the UN about Israel’s “diplomatic and political campaign against Lebanon as a prelude to launch attacks on it.” It accused Israel of hacking its mobile network and sending messages to residents, warning them of bombings.

Hezbollah hasn’t commented so far, with its television channel Al-Manar broadcasting a report from southern Lebanon to show that it was business as usual.

Hezbollah’s closest ally, House Speaker Nabih Berri, described the Israeli allegations as “baseless,” saying Prime Minister Benjamin Netanyahu was using the operation to distract attention from corruption charges he’s facing.

Lebanese Prime Minister-designate Saad Hariri, a staunch opponent of Hezbollah and one of Saudi Arabia’s main allies in the region, said his country did not want the operation on the border to “constitute a reason for any escalation” and that the military was responsible for ensuring safety of the border region.

Tensions between Israel and Iran have been rising over Iran’s entrenchment in Syria, where it has been fighting, largely through Hezbollah, to prop up President Bashar al-Assad. Israel has said it won’t allow its chief regional foe Iran to establish a presence in Syria. Israel and Hezbollah fought a 34-day war in 2006 that killed about 1,200 Lebanese and 165 Israelis.

To contact the reporter on this story: Dana Khraiche in Beirut at dkhraiche@bloomberg.net

To contact the editors responsible for this story: Alaa Shahine at asalha@bloomberg.net, Karl Maier, Michael Gunn

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