Lebanon's health ministry says 200 people are in a critical condition and hospitals are being inundated with the wounded after the pages exploded in people's hands and pockets.

A child is among the dead.

Hezbollah, which has been designated a terrorist organisation by the have called it the biggest security breach.

They have blamed Israel, which has been engaged in cross-border fighting with the Iran-backed group since the start of the war in Gaza almost a year ago.

Israel has not commented.

Paul Adams has the latest and a warning his report contains distressing images from the start.

This was a devastating attack.

In supermarkets, on the street, in cars, at home and even in barber shops, thousands of Hezbollah members simultaneously injured by exploding pages.

Incidents reported from all over Lebanon, from Beirut to the Bekaa Valley and even in neighbouring Syria.

Hospitals suddenly inundated.

Each explosion may have but men lost fingers and eyes.

Some had gaping wounds to their hips where the pages were worn.

Nine people are believed to have died, including one child.

Israel is saying nothing about these extraordinary attacks.

Frankly, it's hard to think of anyone else remotely capable of mounting such a sophisticated operation.

But it comes at a time when the government is threatening to step up its military effort against Hezbollah.

Israel's border with Lebanon has been volatile ever since the war in Gaza began.

Exchanges of fire every day between Israel and Hezbollah.

Tens of thousands of civilians on both sides have been forced to flee.

Kiryat Shmona has been hit several times by Hezbollah rockets.

Israel says its Gaza war aims now include getting Israelis back to their homes close to the border.

The status quo cannot continue, Benjamin Netanyahu said at the weekend.

This requires a change in the balance of power on our northern border.

Today's wave of attacks will have injured Hezbollah's fighters, wrecked their communications and damaged morale.

But will it change the course of this war?

Paul Adams, BBC News, Jerusalem.

The explosions have caused chaos and disbelief across Lebanon.

How could so many devices be made to explode at the same time?

Our security correspondent Gordon Carrera is here.

He's been investigating.

Gordon.

The middle of the afternoon when something extraordinary happens in Lebanon.

Explosions in people's pockets.

So how did it happen?

It appears that was blowing up were these.

Pagers.

Older devices which can receive text messages.

This is believed to be one of the models targeted.

This is the militant group Hezbollah.

This summer it was reported to have given orders for its men to switch away from mobile phones because it feared they could be tracked and calls intercepted.

Instead, they were told to use pagers as they appeared to have been exploited to target them.

This is thought to be one of the pagers that blew up today.

But how was it detonated?

A cyber attack hacking into it remotely to make it overheat would not make a pager explode in the way seen today.

More likely is that the pagers destined for Hezbollah were physically intercepted and had small amounts of high explosive, maybe just a few grams, planted inside ready to be detonated with a signal.

So who was behind damage like this?

Israel has not commented but few have any doubts about its role.

It has used similar methods in targeted killings in the past, killing its enemies with explosives hidden in their mobile phones or in the headrest of their cars.

But no one has ever seen something on the scale of what happened today.

There has been a simmering conflict between Israel and Hezbollah for months.

So what will today's events lead to?

As well as injuring many Hezbollah operatives, this will be a blow to the organisation, making it harder for its people to communicate and spreading fear.

But Hezbollah has vowed to respond.

And so the question is whether that response will lead to an escalation, even all-out war.

Sophie.

Gordon Correra, thank you.