Israeli Prime Minister Benjamin Netanyahu announced Tuesday that an operation launched by the Israeli army on Lebanon's border to destroy suspected Hizbullah tunnels would continue "as long as necessary".
He said the military "holds the Lebanese government responsible for all activities perpetrated in Lebanon towards Israel".
"We are prepared for all options, and the operation is only in its first day".
The Israeli military said its operations were now confined to Israel and did not extend into Lebanon, where it said the tunnels originated. He said the Israeli operation to counter the tunnels would be inside Israel, and would not cross the border.
Last year, Hezbollah's leader said any future conflict with Israel could take place inside Israeli territory, and there would be "no place that is out of reach of the rockets of the resistance or the boots of the resistance fighters".
The tunnels are concentrated in the area around Metula, a small Israeli town of around 1,000 people nestled against the border with Lebanon.
Malene Jensen, spokeswoman for the United Nations force in Lebanon known as UNIFIL, said the situation in the peacekeepers' "area of operation remains calm" and that they are in touch with all relevant parties to make sure calm and stability is maintained. Hezbollah is using Shiite villages to build its infrastructure, and it is impossible to leave the situation as it is. Where you see are Hezbollah operatives filmed inside the terrorist tunnel that was drilled towards our territory.
The official also noted that Hezbollah's course of action will depend on developments in the field.
Israel has been using earthmovers and other large machinery to build a massive wall along its northern border, saying the barrier is needed to protect civilians from Hezbollah attacks. Israel has spent years attempting to tackle a network of tunnels from the Gaza Strip into Israel and has used a variety of methods to destroy tunnels and prevent them from being rebuilt.
Conricus said that while the army has boosted its presence in the north for the Lebanon operation, it has not summoned reserve soldiers. Manelis said the Lebanese Armed Forces is not capable of controlling what occurs in southern Lebanon. Last month he also hinted at an upcoming Israeli offensive during a televised address, but did not give details.
The premier had said that elections now would be "irresponsible" due to the undefined security threats.
Suspicious timing: In Israel and Lebanon, critics of Netanyahu's government are questioning the timing of the operation just as police have recommended that the prime minister be indicted on bribery charges.
Conricus rejected suggestions of politics influencing the announcement. Israel has generally refrained from engaging in Syria's civil war, though it has carried out scores of airstrikes against what Israel says were Iranian shipments of advanced weapons bound for Hezbollah.
However, a friendly fire incident in Syria in September that led to the downing of a Russian plane by Syrian air defences during an Israeli strike has complicated Israeli operations.