United Nations peacekeeping forces on the Israeli-Lebanese border on Saturday confirmed that a tunnel filled up and destroyed by the Israeli army a day earlier had crossed the border into the Jewish state and was in “violation of resolution 1701,” the UN decision that ended 2006’s Second Lebanon War.

It was the third such tunnel that UNIFIL forces confirmed crossed over the Blue Line, which demarcates the internationally recognized border, out of five that the Israel Defense Forces have so far said they have uncovered. UNIFIL has not confirmed Israel’s allegations they were dug by Hezbollah.

The IDF on Friday said it poured an unspecified “liquid” into the underground passage to block it, and aired footage of people in the southern Lebanese village of Kafr Kila reacting to an overflow of viscous material, that some media reports said was cement.

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UNIFIL’s statement on Saturday said that the tunnel opening in Kafr Kila had been inside a cement factory, indicating that the material could have been a mixture of both substances.

“In the course of the ongoing investigation into the presence of tunnels along the Blue Line, UNIFIL together with the Lebanese Armed Forces (LAF) surveyed the premises of an old concrete factory in the southern part of [Kafr Kila], after UNIFIL had observed liquified cement flowing out from the building within this facility,” the peacekeepers said.

“The liquid overflowing on the Lebanese side had been injected by the Israel Defense Forces (IDF) through a shaft drilled on their end of a tunnel that UNIFIL had previously independently confirmed to be crossing the Blue Line in the same general area. Based on this observation, UNIFIL can confirm that the old concrete factory in [the village] has an opening to the tunnel, which is crossing the Blue Line.”

UNIFIL it was working with the Lebanese army to address the violation of the 2006 ceasefire agreement.

UNIFIL added that it had been informed by the IDF on Wednesday of another operation to destroy a tunnel near the Lebanese village of Ayta ash Shab, but that it had not been reported to UN forces prior to its destruction. “Therefore, it’s existence has not been independently verified by UNIFIL.”

The next day “UNIFIL conducted a post-blast assessment and observed a crater in the area.”

The IDF on Friday said Operation Northern Shield was ongoing. The mission, which entered its 24th day on Friday, will continue in order to locate and eliminate additional underground passages dug into Israel from other southern Lebanese villages by the Hezbollah terror organization.

In a phone briefing to reporters, IDF Spokesperson Lt. Col. Jonathan Conricus estimated that the army still needed an additional “few weeks” to complete the operation to destroy the tunnels.

Conricus detailed the two methods the army has been using to neutralize the underground passages: The use of explosives to blow them up — blasts that have been documented in footage the army has distributed to the media — and the pumping of fluid into the tunnels that renders them impenetrable.

Conricus said the army has been able to pinpoint the origin points of the tunnels when the fluid seeped through to the openings on the Lebanese side.

“This fact points to Hezbollah’s use of civilian structures in the heart of built-up areas in southern Lebanon, endangering its citizens as human shields in grave violation of [UN Security Council] Resolution 1701,” the army said.

One of those tunnels was found to have been dug underneath a chicken coop, the army spokesman said.

Citing a 2013 Hezbollah propaganda movie, Conricus claimed the tunnels were part of a three-pronged plan by the Iran-backed terror group to conquer the Galilee. Pointing to the video issued by the terror group’s leader Hassan Nasrallah, the IDF spokesman said the invasion was slated to include a massive barrage of fire on northern Israel, a ground invasion by Hezbollah special forces and a stealthy underground invasion through the organization’s attack tunnels.

The army spokesman clarified that while Israel holds the Lebanese government responsible for the attack tunnels being dug from its sovereign territory, it is clear that Hezbollah was digging the passages.

“The uncovering and destruction of the tunnels has brought significant harm to Hezbollah’s ability to realize its plans,” the IDF said in a statement on Thursday.

Jacob Magid contributed to this report.