Over the last few hours, we've been bringing you updates after Israel began carrying out strikes across southern Lebanon, while the leader of Hezbollah vowed the group would respond to this week's exploding device attacks. Here's what happened today:

• Hezbollah leader Hassan Nasrallah blamed Israel for the attacks - which killed 37 people - saying they crossed all "red lines". Israel has not claimed responsibility
• As Nasrallah started speaking, Israeli jets could be heard flying over Beirut. Israel then confirmed it had launched strikes against Hezbollah targets in Lebanon
• Stories of hospital staff working around the clock to treat those injured in the device attacks continue to come in, with one doctor telling the BBC he had to act "robotic" just to be able to keep working
• The head of the World Health Organisation said the mass explosions "seriously disrupted" Lebanon's "fragile health sector"
• Western diplomats are urging against a widening of conflict - the White House said a ceasefire deal in the Middle East is "achievable", and the UK's foreign secretary, David Lammy, called for an immediate ceasefire between Israel and Hezbollah

We're pausing our live coverage now, but you can continue reading about this story here.

Nafiseh Kohnavard
BBC Persian Middle East correspondent, in Beirut

When Hezbollah leader Hassan Nasrallah’s speech began, almost everyone sitting outside the American hospital in downtown Beirut started watching on their phones.

There are many who have relatives or friends being treated for injures caused by exploding pagers. Most looked exhausted, but they watched Nasrallah's speech carefully.

“I can sacrifice myself for him. He is our leader," Maryam, from Dahieh, told me. Her husband, a Hezbollah member, lost his right hand and both eyes when his pager exploded.

A few minutes after the speech started, we heard a warplane overhead. Israeli jets were flying low over downtown Beirut.

“They are going to strike,” a man shouted, and everyone looked up. Soon after we hear four loud booms – Israeli jets have broken the sound barrier overhead.

“They want to scare us but they can’t,” a young supporter of Hezbollah said. But the panic was visible on some people's faces.

A man, 62, whose son, a doctor, was injured as he had a pager while working at a hospital managed by Hezbollah, told me: “We are not in a position that expects anything from our leader. Whatever he decides is for the benefit of our people, and we will support it.”

He added: “We are not Hezbollah members. My son was not Hezbollah member, but we are supporters of the resistance and will stay that way no matter what".

But there are concerns among many Lebanese that the country is going towards a war - a war that in some people’s eyes only Hezbollah will be responsible for.

Orla Guerin
Senior international correspondent, reporting from Beirut

Image source, Reuters

A Lebanese surgeon has described how the sheer volume of severe wounds from two days of exploding device attacks forced him to act "robotic" just to be able to keep working.

Surgeon Elias Jaradeh said he treated women and children but most of the patients he saw were young men. The surgeon said a large proportion were “severely injured” and many had lost the sight in both eyes.

The dead and injured in Lebanon include fighters from Hezbollah, but members of their families have also been killed or wounded, along with innocent bystanders. Dr Jaradeh described the wounded he treated as looking "mostly civilian".

Dr Jaradeh, who is also an MP for the Change parliamentary bloc, was working at a specialist eye and ear hospital where some of the most severely wounded people were sent. He said it had taken a toll on the medical teams, himself included.

"It's very hard," the surgeon said. "You have to dissociate yourself. More or less, you are robotic. This is the way you have to behave, but inside, you are deeply injured. You are seeing the nation injured."

Read more here.

UK Foreign Secretary David Lammy has called for an immediate ceasefire between Israel and Hezbollah.

"Tonight I'm calling for an immediate ceasefire from both sides," Lammy tells the Reuters news agency, after meeting his French, American and Italian counterparts for talks in Paris.

"We are all very, very clear that we want to see a negotiated political settlement so that Israelis can return to their homes in northern Israel and indeed Lebanese to return to their homes."

It comes after he earlier urged British nationals in Lebanon to leave "while commercial options remain".

The US believes a diplomatic solution in the Middle East "achievable" and "urgent", the White House says.

Press Secretary Karine Jean-Pierre told reporters during a regular briefing in Washington that a ceasefire deal would "lower the temperature" in the region.

"We want to have a diplomatic resolution here to the tensions that we are seeing in the Middle East, we do not want to see an escalation, we believe that's achievable and obviously it's incredibly urgent," she says.

The first round of blasts began in Lebanon's capital Beirut and several other areas of the country at about 15:30 local time (13:30 BST) on Tuesday.

Witnesses reported seeing smoke coming from people's pockets, before seeing small explosions that sounded like fireworks and gunshots.

Citing US officials, the New York Times said that the pagers received messages that appeared to be coming from Hezbollah's leadership before detonating. The messages instead appeared to trigger the devices, the outlet reported.

Explosions continued for around an hour after the initial blasts, the Reuters news agency reported.

Soon after, scores of people began arriving at hospitals across Lebanon, with witnesses reporting mass confusion in emergency departments.

Similar scenes played out across the country in another round of blasts on Wednesday, at around 17:00 local time (15:00 BST).

Reports suggest it was walkie-talkies that were blown up, devices that were purchased by Hezbollah five months ago, according to a security source speaking to Reuters news agency.

Read more here.

The Lebanese mission to the UN says the communication devices which exploded in Lebanon this week were detonated by electronic messages, the Reuters news agency reports.

A preliminary investigation by Lebanese authorities also found that the devices were implanted with explosives before arriving in the country, Reuters says.

Israel's army says it hit about 30 Hezbollah rocket launchers in air strikes carried out in Lebanon.

In a statement, the Israeli Defense Forces (IDF) says that it also struck "a weapons storage facility in multiple areas in southern Lebanon" which it claims contained "approximately 150 launcher barrels that were ready to fire projectiles toward Israeli territory".

Tom Bateman
State Department correspondent, in Washington DC

I’ve just come from the US Department of State press briefing, where I tried to pin down a few more basic facts from the spokesman, Matthew Miller.

It follows anonymous briefings from US officials we reported on yesterday suggesting Israel did in fact tip off Washington ahead of Tuesday’s attacks that it was about to do “something” in Lebanon, but gave no details of the operation.

On Tuesday, Miller said the US “was not aware of this incident in advance”. I just asked him if that was still correct and he said: “The statement I made on Tuesday was 100% accurate”. The US says it's still “gathering information”.

I pressed Miller on whether Washington sees the attacks as consistent with international humanitarian law which prohibits uses of booby-traps in the form of “harmless portable objects”.

Miller said: “We take into account all the relevant provisions of international humanitarian law when we assess incidents of this type… I don’t pronounce judgement on those from this podium”.

The US remains in a holding pattern – stalling on saying anything beyond the most basic comments (it is not even publicly attributing the attacks to Israel) – while it decides on its next moves to help shield its ally from the potential repercussions.

Nafiseh Kohnavard
BBC Persian Middle East correspondent, in Beirut

In downtown Beirut, near one of the hospitals that patients of pager devices explosions are being treated, Lebanese soldiers have been suddenly asking people to move back.

They have blocked the road with their army trucks. “Soon there will be an explosion” one soldier shouts. “Stay away.”

In one area, we found out that there would be controlled detonation of a “suspicious” pager that was identified in the area. The soldiers didn’t give us more details of where the device was found.

An army detonation specialist in full protective gear used a remote-controlled bomb disposal robot. People were anxiously watching while some tried to take cover.

“Explosion, explosion, explosion” an officer shouted in Arabic. A few seconds later, we heard a loud noise. “It was definitely lauded with explosive” another officer told me.

Some began to run away fearfully from where the sound came, while others tried to calm the frightened people down.

“That’s over. Don’t be scared,” a woman told one girl that was screaming. I found out that the woman’s husband was injured on Tuesday when the pagers being used by Hezbollah started to explode.

“Just imagine if this happens inside your house” she told me.

Nick Thorpe
Central Europe correspondent, in Budapest

Bulgaria's state security service DANS has issued a statement in response to claims that a Bulgarian registered company, Norta Global Ltd, was involved in the sale of pagers to Lebanon, which exploded on Tuesday.

"No customs operations with communication devices (pagers) that were detonated on the territory of Lebanon and Syria have been carried out through the territory of Bulgaria," the statement reads.

In other words, it's saying the pagers were neither manufactured nor exported from Bulgaria.

DANS is also carrying out "joint inspections with the National Revenue Agency and the Ministry of the Interior," the statement continued.

Norta Global appears to be a letter box address with just one named director, a Norwegian lawyer. The company was set up in 2022.

A Hungarian company, BAC Consulting, was named on Wednesday by Gold Apollo, the Taiwanese company whose logo was found on some of the devices which exploded, as the subcontractor for the devices, but the Hungarian prime minister said the company in question had "no manufacturing or operational capacity" in Hungary, and is just a "trading intermediary".

Image source, Reuters

Hezbollah is a politically-influential Shia Muslim organisation which controls the most powerful armed force in Lebanon.

It was established in the early 1980s by the region's most dominant Shia power, Iran, to oppose Israel. At the time, Israel's forces had occupied southern Lebanon during the country's civil war.

Hezbollah has participated in national elections since 1992 and has become a major political presence.

Its armed wing has carried out deadly attacks on Israeli and US forces in Lebanon. When Israeli troops withdrew from Lebanon in 2000, Hezbollah took credit for pushing them out.

Since then, Hezbollah has maintained thousands of fighters and a huge missile arsenal in southern Lebanon. It continues to oppose Israel's presence in disputed border areas.

The group is designated a terrorist organisation by Western states, Israel, Gulf Arab countries and the Arab League.

Read more about Hezbollah here.

Image source, PA Media

UK Foreign Secretary David Lammy has again asked for British nationals in Lebanon to leave now "while commercial options remain".

"Tensions are high and the situation could deteriorate rapidly," the foreign secretary says in a post on social media. A similar plea he made on 30 July, saying at the time that tensions in the country could escalate with "little warning".

Lammy says he has spoken to the Lebanese prime minister following the deadly blasts in the country to express "deep concern over rising tensions and civilian casualties".

Image source, Reuters

We can now bring you some reaction from US Secretary of State Antony Blinken, who is in Paris for talks on the situation in the Middle East with his European counterparts.

"France and the United States are united in calling for restraint and urging de-escalation when it comes to the Middle East in general and when it comes to Lebanon in particular," he says.

The top American diplomat says Washington and Paris "continue to work to get a ceasefire for Gaza over the finish line".

"We believe that remains possible and necessary. But meanwhile we don't want to see any escalatory actions by any party that makes that even more difficult," Blinken adds.

• 'Red lines' crossed: In a televised address, Hezbollah leader Hassan Nasrallah blamed Israel for this week's walkie-talkie and pager detonations. He said the blasts - which killed at least 37 - crossed all "red lines". He vowed Hezbollah would respond. Israel has not directly commented on the attacks
• Israel strikes: As Nasrallah started speaking, BBC Middle East correspondent Hugo Bachega reported hearing huge sonic booms as jets flew over the Lebanese capital, Beirut. Soon after, Israel announced it had launched fresh strikes on Hezbollah targets in Lebanon
• War in 'new phase': Israel's Defence Minister Yoav Gallant told a briefing with Israeli military officials that action against Hezbollah "would continue", but with "significant risks"
• Healthcare disrupted: Meanwhile, the World Health Organisation chief said the mass explosions "seriously disrupted" Lebanon's "fragile health sector"

Stay with us for more.

Image source, Reuters

Israel's Defence Minister Yoav Gallant has said Israeli military action against Hezbollah "will continue".

"In the new phase of the war there are significant opportunities but also significant risks. Hezbollah feels persecuted. The sequence of our military actions will continue," Gallant said during a briefing with Israel Defense Forces officials.

"Our goal is to ensure the safe return of Israel’s northern communities to their homes. As time goes by, Hezbollah will pay an increasing price," he added.

The mass explosions of communication devices in Lebanon this week "seriously disrupted" its "fragile health sector", the World Health Organization (WHO) chief says.

Speaking at a news conference, Tedros Adhanom Ghebreyesus says that the global body distributed blood supplies and trauma kits in the country.

WHO emergencies chief Mike Ryan adds that the health system "came under immense pressure very, very quickly".

The Israeli military says two of its soldiers have been killed near Israel's northern border with Lebanon.

The two men, aged 43 and 20, "fell in combat", it says in a statement, adding that they were killed near the Lebanon border.

Hezbollah leader puts on brave facepublished at 16:39 British Summer Time 19 September

16:39 BST 19 September

Paul Adams
Diplomatic correspondent, reporting from Jerusalem

Hassan Nasrallah put the bravest possible face on what has undoubtedly been one of the darkest moments in Hezbollah’s history.

He claimed, perhaps improbably, that the group’s communications networks had survived unscathed, and he mocked this week’s reports that the head of Israel’s Northern Command, Maj Gen Ori Gordin, is pushing for the creation of an Israeli-controlled buffer zone in southern Lebanon.

Nasrallah called Gordin a “fool”. Israel’s threat, he said, would turn into Hezbollah’s opportunity, which would have “dire consequences” for Israel.

Key takeaways from Nasrallah's speechpublished at 16:17 British Summer Time 19 September

16:17 BST 19 September

Hugo Bachega
Middle East correspondent, in Beirut

Image source, EPA

Hassan Nasrallah’s much anticipated speech, his first public reaction since the wave of attacks in Lebanon in the last couple of days, had, as expected, some strong words against Israel.

Referring to the country, he said “the enemy” had exceeded “all limits, rules, and red lines” with the explosions that killed at least 37 people and injured more than 3,000 others.

He described the attacks as a massacre, and acknowledged that this was an unprecedented blow for the group but that its ability to command and communicate remained intact.

An investigation into how it happened has been launched, he added.

“It can be called war crimes or a declaration of war - whatever you choose to name it, it is deserving and fits the description. This was the enemy's intention,” he said.

He vowed a just punishment but, unsurprisingly, there was no indication of how this response is going to be. The cross-border attacks on Israel will continue unless there is a ceasefire in Gaza, he added, saying that the residents in northern Israel who have been displaced because of the violence will not be allowed to return.

The tone, again, indicated that the group will measure its reaction in order to not spark a major war with Israel, which would be destructive not only for the group but also for Lebanon, a country struggling to recover from multiple crises in recent years.