Israel's defense minister says the country is opening a new phase in the war and the center of gravity is shifting to the north. His warning came hours after a second wave of blasts swept across Lebanon. Exploding walkie talkies left at least 20 dead and more than 450 injured. Yesterday, hundreds, maybe thousands of electronic pages used by the armed group Hezbollah detonated simultaneously, killing at least 12 and leaving more than 3,000 in hospital. Tonight, our security correspondent, Gordon Carrera, looks at this new form of technological warfare. I'll be talking to our international editor, Jeremy Bowen, amid grave fears this is about to escalate across the Middle East. Today, a division of the Israeli Army has relocated from Gaza to the north of Israel, reinforcing troops there. Well, let's go straight to Beirut now. Our senior international correspondent, Ola Guirin, is there. Ola.

Sophie, tonight we are in new territory. This is a new phase of the war. Israel says so. Hezbollah, which is classed as a terrorist organization by the UK and the US, is also saying the same. Here on the streets today in Beirut, in the Hezbollah stronghold of Dahlia, we saw fear and chaos and panic when reports started coming in of a second wave of explosions. Casuities were being rushed away for treatment. One young member of Hezbollah said, This It was a terrible time for us. We have never seen anything like it. We are encouraging our supporters to get off the streets to go home to try to stay safe. Now, in the past 24 hours, Hezbollah's communication networks have been shattered by Israel. But it would be a mistake to say that the organization is defeated. Far from it. It's promising revenge, and we expect to hear more about that tomorrow in a speech by its leader, Hassan Nasrallah.

Hasbollah coming to bury its dead in South Beirut today. Casuities of a new chapter in Middle East warfare. Killed not by airstrikes, but by exploding pagers. Apparently, a message from Mossad. Among the dead, an 11-year-old boy. But even the mourners weren't safe. Suddenly, the sound of another blast. Chaos and panic filling the street, and a rush to evacuate one of the wounded. The authorities say this time walkie-talkies exploded, not just in Beirut. Here at a cell phone shop in the Southern city of Saiden. Israel is being blamed for the past 24 hours of unprecedented attacks.

Well, one more ambulance there, passing by.

We've been seeing them in the last half an hour or so. Also, fire brigade trucks. People have been looking at the sky, worried there are drones. They're beginning to leave the area to get off the streets.

The attacks began yesterday afternoon, with explosions in food markets, in homes, in restaurants. Soon, casualties were streaming to hospitals, almost 3,000 wounded in an hour. Doctors say many lost fingers, and many were blinded.

It has been a nightmare. Probably this is the worst day of my life as a physician. Unfortunately, we were not able to save a lot of eyes. I can tell you that probably more than 60 to 70% of the patients ended up with eviscerating or removing at least one of their eyes. We're talking about young population, about patients in their 20s.

From Israel, no admission of responsibility. But the defense minister Here, Yoav Galant says a new phase of the war is starting. Hezbollah, which is Iranian-backed, has been waging war with Israel since last October, the two sides trading fire across their shared border. Over the past 24 hours, Hezbollah has been shaken and humiliated, but it's still better armed than many nations. Israel, too, has plenty of fire power, and today, released this footage of its troops training near the Lebanese border. A source told the BBC that a second division of the army has moved to the area. There are growing fears of an all-out war. Orlegeran BBC News, Beirut.

Well, these ongoing attacks have stunned people in Lebanon and caused widespread fear. Our security correspondent, Gordon Carrera, has been looking at this new form of technology biological warfare. And he's with me now, Nour Gordon.

These have been extraordinary attacks, taking communications devices people carry around and turning them into weapons to be used against them. Today, handheld videos, walkie-talkies, were exploding suddenly in Lebanon. This was what was left of one of them. It follows yesterday afternoon when thousands were injured by small explosions in people's hands and pockets. This was the culprit, a Pager, which can receive text messages. Pagers and walkie-talkies are old-school technology, but something Hezbollah turned to recently because it feared its mobile phones could be tracked. This map details the locations injuries sustained in yesterday's attack, the vast majority in the capital Beirut. But how was it done? Today, Washington said it didn't know. The United States did not know about, nor was it involved in these incidents, and we're still gathering the information and gathering the facts. So what do we know? If we look at the debris of this pager, you can see part of a brand name here. It's Gold Apollo. Now, that That's a company based all the way over here in Taiwan. The owners today said they'd not made the pages involved, though. Instead, they had licensed making them to another company called the BAC Consulting.

Now, BAC Consulting is based in Budapest, the capital of Hungary, and the BBC's nick Thorpe went to visit today.

This is the registered address of BAC Consulting here in Budapest. In fact, there's very little sign that they're based here at all. Just a piece of paper with their name alongside 12 other company names behind the geraniums. Very few people have been coming in and out of this building all day. No one seems We don't know anything about this company at all.

So this is debris left from a pager after it exploded. So Israel looks to have intercepted the supply this year of thousands of Pagers to Hezbollah and hid tiny amounts of high explosive inside. A signal was then sent, which meant five seconds after a Pager buzzed to say there was a message, it blew up. Something similar may have happened with the radios today. Supposedly Japanese made, they also arrived a few months ago. But why now? One theory is that Israel's spy agency Mossad had put in place the capability to be used in the event of an all-out conflict in neighboring Lebanon. But Hezbollah became suspicious about the pages, and so Mossad decided it was a case of use it or lose it, triggering first the pages, and then today, the radios. If that's right, then it's not quite clear whether there is a wider plan behind launching the attack. It has sown confusion and fear and inflicted many injuries, but it may also spark a response.

Sophie. Gordon. Thank you. Well, our international editor, Jeremy Bowen, is with me now. It's almost exactly a year since the October the seventh of the attacks. How dangerous a moment is this for the Middle East?

I'd say really dangerous, as dangerous as any in the last almost 12 months since those Hamas attacks, which, by the way, this last year has been the most dangerous year since 1948, when Israel fought and won for its independence. Why is it so dangerous right now? Well, that's because at the moment there seems to be no possibility of diplomacy getting through and de-escalating situation. That's because it depends on a ceasefire in Gaza, and that isn't happening either. Now, while Israel has scored a really significant tactical victory here, there is a potential longer term serious strategic downside because Israel has humiliated its enemy in Lebanon. There's no question about that, but it doesn't get Israel closer to its strategic aims, the things it wants to do. That is to stop the rocket fire over the border into Israel. 60,000 plus people People have been evacuated for almost a year from their homes as a result of that. They want to go home, and they want to push Hezbollah as well back away from the border. I do not see how these attacks get Israel closer to that. Now, Israel, of course, defends itself. Self-defense against a terrorist organization is what it would say.

But there are plenty of people criticizing Israel as well for using force somewhat indiscriminately, as well as hitting military targets, those Hezbollah fighters, Also hitting members of their family, killing children, killing bystanders in markets. So Israel under pressure with that. And one more thing as well, the UN General Assembly is sitting at the moment in New York, and there was a big vote today, and by a vote of 123 to 14 with 43 abstentions, the General Assembly supported a Palestinian resolution saying that Israel must end its unlawful presence in the occupied territories year. It's non-binding, but it shows just how isolated the Israelis are.