AMNA NAWAZ: For the second time in as many days, an unprecedented shocking attack on the Iran-backed Lebanese militant group Hezbollah.

Yesterday, Hezbollah pagers exploded.

Today, it was walkie-talkies used by some group members.

Lebanese officials say the two attacks killed more than 20 and injured more than 3,000 people.

Nick Schifrin is here now following that story -- Nick.

NICK SCHIFRIN: Amna, a U.S. official confirms to me that Israel has briefed the United States that it was behind the attacks yesterday and today which hit Hezbollah even as it was burying its dead.

Today, as thousands mourned at a Hezbollah funeral, they had to plan another one.

Hezbollah walkie-talkies across the country exploded in Hezbollah members' hands in Beirut cell phone shops and turned scooters into char.

The attacks were aimed at Hezbollah militants, but exploded in civilian areas, even in Beirut living rooms, affecting families across the country.

They will further inflame Hezbollah and its followers one day after thousands of Hezbollah pagers blew up in markets, at cash registers, hitting militants where they're most vulnerable, Hezbollah communications networks tonight apparently compromised, and thousands of its rank and file injured, the group in disorder and demoralized.

At the funerals today, a shocked and humbled Hezbollah vowed revenge.

HASHEM SAFIEDDINE, Hezbollah Executive Council (through translator): This aggression inevitably has its own punishment.

It has its own retribution.

This punishment will come, God willing.

NICK SCHIFRIN: Officially, Israel has not taken responsibility, but a U.S. official confirms Israel informed the U.S. it was behind yesterday's and today's attacks.

Today, Israeli Prime Minister Benjamin Netanyahu released a one-sentence statement.

BENJAMIN NETANYAHU, Israeli Prime Minister (through translator): I have said it before.

We will return the citizens of the north to their homes safely, and that's exactly what we're going to do.

NICK SCHIFRIN: Sixty thousand Israelis fled their Northern Israeli homes after Hezbollah opened fire after October the 7th.

There is widespread anger at the government, but they are still displaced.

Today, Defense Minister Yoav Gallant, rumored just yesterday to soon be fired, said the government was united in shifting the war's goals away from Gaza.

YOAV GALLANT, Israeli Defense Minister (through translator): The center of gravity is moving north, meaning that we are allocating forces, resources and energy for the northern arena.

I believe that we are at the start of a new phase in the war, and we must adapt.

NICK SCHIFRIN: The U.S. has tried to prevent all-out Israel-Hezbollah war with shuttle diplomacy to try and convince Hezbollah to move back from the border alongside a larger Gaza cease-fire.

In Cairo today, Secretary of State Antony Blinken called for restraint.

ANTONY BLINKEN, U.S. Secretary of State: We remain very clear about the importance of all parties avoiding any steps that could further escalate the conflict that we're trying to resolve in Gaza.

NICK SCHIFRIN: Today, the Taiwanese manufacturer of the pagers involved in yesterday's incident said, while its brand appeared on the pagers, they were actually manufactured by a company in Hungary.

Israelis assumed to have infiltrated the supply chains to implant small explosives in both the pagers and the walkie-talkies.

To discuss all this, I'm joined by Hanin Ghaddar, the Friedman senior fellow at the Washington Institute for Near East Policy, a think tank in Washington, D.C. Hanin Ghaddar, thank you very much.

Welcome back to the "News Hour."

As I was just reporting, thousands of Hezbollah-injured, communications networks completely infiltrated.

What kind of impact will these two days of attacks have on the group?

HANIN GHADDAR, Washington Institute for Near East Policy: This is, I think, the biggest blow to Hezbollah in terms of security breach by Israel.

It's on many levels, because these pagers, what we understand so far is that these 5,000 pagers that were intercepted and sent to Hezbollah and exploded, they were given to Hezbollah's senior leadership and -- mid-level and senior leadership.

So it's not for every person in Hezbollah.

So the hit was really high in their ranks.

And today's attacks also showed them that they still do not understand how infiltrated they are by the Israeli intelligence.

This is just on the technical level, on the communication network.

NICK SCHIFRIN: Israel is signaling a ramping up of pressure on the Israeli-Lebanese border.

What do you believe is the Israeli goal behind these attacks?

HANIN GHADDAR: So, it seems that the appetite for war is increasing from Israel towards Lebanon.

And any provocation by Hezbollah today, any kind of a wider response is going to probably get Israel to widen its attacks in Lebanon.

War can come in many colors and shades.

I don't think this is just a message of deterrence.

This is something that would lead Israel to go more into Hezbollah's escalation against Hezbollah, especially after we saw not just statements from Israel, but also movement of their military from Gaza to the borders of Lebanon.

NICK SCHIFRIN: And in that sense, Hezbollah is more likely to almost play into that, right?

This attack traumatized Lebanese civilians in an unprecedented way.

Lebanese families were hit.

We saw a video of some of these explosions inside homes.

Is Hezbollah under more pressure to respond in a big way because of that trauma?

HANIN GHADDAR: They definitely are under much more pressure today to respond because they have been humiliated.

But the problem is that for them to respond, they need to reconstruct their military capabilities, including their communication system.

So it might take some time.

But also nothing has changed in terms of using -- of not using their military assets, which is the precision-guided missiles, because they are still there to ensure Iran's stability, Iran's insurance policy in Lebanon.

So nothing has changed in that sense.

But they have to do something, because they lost the respect of their own community after this.

They're totally humiliated.

The trust levels are completely eroded with their community and against each other.

They need to do something.

But they're also cornered in the sense of how to do it without inviting Israel to a full scale in Lebanon.

It's a dilemma.

NICK SCHIFRIN: And U.S. officials certainly believe still that Hezbollah -- neither Hezbollah nor Iran want a full-scale war.

We will hear from Hassan Nasrallah, the head of Hezbollah, tomorrow.

HANIN GHADDAR: Yes.

NICK SCHIFRIN: What do you predict his message will be?

HANIN GHADDAR: He has to speak.

There's no way after this incident -- every time something big happens, he addresses his people or addresses the enemy sometimes.

So, tomorrow, he has to speak, whether he has something important to say or not.

What I think is going to happen is that he will say they will respond.

I don't think they already have a response yet because, again, it takes time for them to assess what they have lost and what they can do.

But he will threaten Israel.

He will say that they will respond.

It's like last time they endured something like this with the assassination of Fuad Shukr, the top... NICK SCHIFRIN: The number three in Hezbollah whom Israel assassinated in Southern Beirut.

HANIN GHADDAR: Exactly.

I think it is -- a speech, an angry, threatening speech like that will happen tomorrow, but not necessarily a response that will follow immediately afterwards.

They need time to figure this out.

NICK SCHIFRIN: Hanin Ghaddar of the Washington Institute for Near East Policy, thank you very much.

HANIN GHADDAR: Thank you.