A Spanish UNIFIL peacekeeper drives an armored vehicle in the Lebanese town of Adaisseh, near the border with Israel, on January 19, 2015.
The situation appeared calm on the Lebanese side of the border where United Nations peacekeepers and Lebanese troops were deployed as usual, a Reuters journalist there said.
"UNIFIL is liaising with all relevant interlocutors to ensure that the parties use the UNIFIL liaison and coordination mechanisms to maintain the continued calm and stability", she said.
An army spokesperson declined to say how many "attack tunnels" had been identified or by what means they would be cut off.
For its part, the Hezbollah terror group has remained largely quiet.
Its Arabic media spokesman posted a message on Twitter warning the Lebanese army and Hezbollah to stay away, saying: "Your lives are in danger, you have been warned".
Hezbollah is also a powerful political party in Lebanon.
"Netanyahu is in a jam because of [his government's] crisis and is tilting at windmills", the unnamed official told the Lebanese outlet, referencing the literary character Don Quixote.
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.
The IDF said that "Operation Northern Shield" was initiated under a special task force that has since 2014 been leading operational, technological and intelligence efforts on the issue of tunnels on the northern border and has "developed vast abilities and knowledge on Hezbollah's attack tunnel project".
The photographs appeared to have been taken from watchtowers along the Israeli-Lebanese border, which are meant to be used exclusively by the Lebanese Armed Forces.
Additional IDF troops were deployed to northern Israel as a precaution against potential attacks by Hezbollah, but no reservists were called up.
"The Hezbollah terror organization, which is responsible for digging the cross-border attack tunnels, continues activity that is supported and funded by Iran, to establish its terror infrastructure against Israeli civilians".
Conricus, however, said the tunnels "are not yet operationally ready" and therefore did not pose an "immediate threat".
The tunnels were dug "from within civilian houses in Lebanon into Israel", Conricus said, calling it a tactic that was born out of the end of the 2006 war. In recent years, Israel has destroyed dozens of tunnels dug by Hamas under their shared border.
In response to the operation, Hezbollah said it would not change its behavior in southern Lebanon, according to Ynet News.