Israel announced on Tuesday that it discovered a third Hezbollah tunnel under its border with Lebanon since it kicked off operation Northern Shield a week ago. The Israeli army did not disclose where the new tunnel was discovered, adding that it did not pose an “imminent threat” to Israeli residents living in border regions. The military said its soldiers placed explosives in the tunnel, warning Hezbollah against entering it. Israeli Prime Minister Benjamin Netanyahu visited the border area where the third tunnel is located. "If Hezbollah makes the big mistake and decides in any way to harm us or to resist the operation we are conducting, it will be hit in a way it cannot even imagine," he warned. "We will pursue this operation as long as the threat of Hezbollah tunnels persists," the premier, who was accompanied by the army chief of staff, said in a statement released by his office. Netanyahu said an Israeli army delegation would be visiting Moscow to brief Russian counterparts on operation Northern Shield. He said the delegation, would also explain "as clearly as possible that Israel has the right and the duty to fight against Iranian military presence and act against Hezbollahs bid to attack through tunnels". Earlier, Lebanese President Michel Aoun said that the Israeli operation will not endanger the calm along the frontier, adding that his country takes the issue seriously. The United Nations Interim Force in Lebanon (UNIFIL) confirmed the presence of two tunnels along the border. The missions head, Major Stefano Del Col, said he met with Aoun and parliament Speaker Nabih Berri Tuesday and informed them that UNIFIL experts have inspected two tunnels near Metulla, along the border north of Israel. "This is a serious matter and UNIFIL is working in close coordination with the parties both at the technical level as well as at the leadership level to ensure that all related facts are objectively determined and diligently addressed in line with UN Security Council Resolution 1701," Del Col said in a statement. Aoun, a Hezbollah ally, said that Lebanon is prepared to address the issue after assessing a full report on the situation. He said the United States has informed Lebanon that Israel has "no aggressive intentions," adding that his country harbored none either. Israel launched operation Northern Shield on December 4 to destroy a series of tunnels, showing one to UN peacekeepers and calling it a violation of the ceasefire that ended the 2006 war with Hezbollah. De Col said the inspection of tunnels is a "work in progress" and vowed that UNIFIL will "make every effort to maintain clear and credible channels of communication with both sides so that there is no room for misunderstanding on this sensitive matter."