Beirut, Lebanon — The White House has warned both Israel and the Iran-backed Hezbollah group against “escalation of any kind” following this week’s synchronized pager and walkie talkie explosions targeting Hezbollah members, but overnight, Israeli warplanes carried out dozens of strikes across southern Lebanon, and Hezbollah has continued firing back.

There were loud explosions and fires ignited by what the Israel Defense Forces said were strikes targeting hundreds of active Hezbollah rocket launchers in Lebanon early Friday. 

It appeared to be one of the most extensive Israeli attacks on Hezbollah’s stronghold in southern Lebanon since the two sides started trading fire 11 months ago, with Hezbollah claiming its rocket attacks on northern Israel as support for its allies Hamas and the Palestinian people.

Hezbollah struck northern Israel again in a counterattack, killing at least two soldiers, according to Israeli officials.

The deadly escalation in violence followed a televised address from a weary-looking Hassan Nasrallah — the leader of Hezbollah — who admitted this week’s pager and walkie talkie explosions had delivered a “severe blow” to the powerful group, which like Hamas has long been designated a terrorist group by Israel and the U.S.

Nasrallah accused Israel of not only violating “all red lines” with the explosions, but of a “declaration of war.”

Israel has not publicly claimed the complex attacks, but CBS News learned that American officials were given a heads-up by Israel about 20 minutes before the operations began in Lebanon Tuesday, though there were no specific details shared about the methods to be used.

For two terrifying days in Lebanon, thousands of low-tech communications devices — many used by Hezbollah members — exploded simultaneously across the country, wounding over 3,000 people and killing at least 37, including children, according to Lebanon’s health ministry.

In his address, Nasrallah vowed that Israel would not achieve its goal of enabling the return of tens of thousands of people displaced from their homes in northern border towns. Even as he spoke on Thursday, however, sonic booms echoed above Beirut as Israeli fighter jets roared over the city, flexing Israel’s military might.

But as the U.S. warning Thursday indicated, the next moves — be they further retaliation from Hezbollah or ground operations by the IDF against the group — could have major consequences.

“Ultimately, if they [Israel] do invade, they would have to occupy” southern Lebanon, regional analyst Makram Rabah told CBS News. “This would lead to a kind of a slow, depleting war for Israel, and this would, more importantly, legitimize Hezbollah.”

But hundreds of Hezbollah fighters were likely injured by the explosives attacks, which almost certainly left the group’s communications networks in complete disarray. And despite warnings from Israel’s defense chief of “a new phase” in the country’s war with Iran’s so-called proxy groups, and one IDF division already being transferred there from Gaza, there’s also been no major Israeli build-up of forces or hardware along the Lebanon border seen yet.

So, the prospect of all-out war between Hezbollah and Israel — which could potentially put U.S. forces across the Middle East in direct danger — may not be as close as some fear.

contributed to this report.

Imtiaz Tyab

Imtiaz Tyab is a CBS News correspondent based in London and reports for all platforms, including the “CBS Evening News,” “CBS Mornings,” “CBS Sunday Morning” and CBS News 24/7. He has extensive experience reporting from major global flashpoints, including the Middle East and the war on terror.