Carine Torbey
BBC Arabic correspondent, in Beirut

Image source, Reuters

Since the start of the latest escalation, around 300,000 people have crossed into Syria to flee Israeli air strikes. Most of them took the Masnaa crossing.

Cutting off that road will mean further pressure on civilians - Lebanese and Syrians alike.

The Israeli army says it has struck an underground tunnel crossing that enables the smuggling of weapons, but the Lebanese minister of works has said the crossing is civilian and under the state’s authority.

He also warned that Lebanon could face a siege by air and by land, following the targeting of the road and calls on the international community to take action.

The targeting of the crossing will not only affect the movement of people but also of goods.

There are other crossings between Syria and Lebanon, but Masnaa is the most important and prominent one.

In the last four days, 250 Hezbollah members have been killed by the Israel Defense Forces (IDF), it says in a statement.

Twenty-one of those killed were commanders, according to the statement, and more than 2,000 military targets have been attacked.

It adds its activity is focused on southern Lebanon.

According to US media, a key target of last night's overnight strikes in Lebanon was Hezbollah's next potential leader, Hashem Safieddine. This has not been confirmed and his condition is unknown.

Lebanon's health ministry said more than 2,000 people have now been killed since last October. More than one million people have been displaced in the country.

Hugo Bachega
Middle East correspondent, in Beirut

The massive overnight Israeli airstrikes in Beirut are believed to have targeted the man expected to take over as Hezbollah’s leader: Hashem Safieddine.

He was reportedly in an underground bunker, and his fate is still unclear.

This morning, an Israeli attack cut off a road leading to the main crossing between Lebanon and Syria. The Israeli military said it had struck an underground tunnel that was being used for the transfer of weapons.

In the south, the hospital in the town of Marjayoun has been evacuated after an Israeli airstrike nearby. Hezbollah, too, has been firing more rockets into Israel.

As the conflict continues, a crisis created by more than one million displaced people is worsening. The UN says most of Lebanon’s nearly 900 shelters are full, and a rising number of people are sleeping in streets or public parks.

We've been seeing pictures of pallets of aid, some labelled with the World Health Organization (WHO), being unloaded from a plane in Beirut.

Yesterday, the WHO's director-general called on "all partners to facilitate flights, external to deliver much-needed life-saving supplies to Lebanon".

In a post on X this afternoon, the Lebanese Army says a plane with food aid - donated by Romania - has arrived in Beirut.

Image source, EPA

Image source, EPA

Image source, EPA

Iran's foreign minister in Beirut as strikes continuepublished at 13:50 British Summer Time 4 October

13:50 BST 4 October

Nafiseh Kohnavard
Middle East correspondent, in Beirut

Iran’s Foreign Minister Abbas Araghchi is in Beirut - landing only a few hours after series of massive air strikes on southern suburbs of the city. In the past few minutes, more have been reported.

This is the first official and announced visit by a high ranking Iranian politician since Israel targeted and killed Hezbollah leader Hassan Nasrallah.

After he landed, he said Iran backed efforts for a ceasefire in Lebanon if Hezbollah support it - and if it coincides with a ceasefire in Gaza.

Araghchi is in Beirut at a time when nothing looks in favour of the Islamic Republic of Iran.

Some here blame Iran for "putting Hezbollah under pressure" to take part in Hamas's fight with Israel after 7 October, but didn’t provide the support that the group needed..

Although Iran’s recent attack created a moment of excitement for the supporters of Tehran and Hezbollah, that mood was temporary and now again there are criticisms in the media and on the streets.

On the other hand, anti-Hezbollah parties see this as a war that Iran brought to them.

During his meeting with Lebanese Prime Minister Najib Mikati, Araghchi says: "Iran will launch a diplomatic campaign to support Lebanon", Lebanese media report.

But for such a campaign, one should have cards in hand to play. For years Iran’s cards were allied paramilitary groups like Hezbollah. At the moment, it is hard to see how that campaign will be done and how that will work, when Iran itself now is on the verge of becoming a target in this war.

Two more strikes have been carried out on south-eastern Beirut, our team there reports.

The Israel Defense Forces has not commented yet.

The latest images coming in from Lebanon reveal the extent of the damage left in the wake of intense Israeli strikes on its capital, Beirut.

The Mreijeh neighbourhood, located in the southern suburbs of the city, is pictured below:

Image source, EPA-EFE/REX/Shutterstock

Image source, EPA-EFE/REX/Shutterstock

Image source, EPA-EFE/REX/Shutterstock

Image source, EPA-EFE/REX/Shutterstock

Image source, Reuters

Khamenei tries to project strength, calm and unitypublished at 12:53 British Summer Time 4 October

12:53 BST 4 October

Shayan Sardarizadeh and Ghoncheh Habibiazad
BBC Monitoring

Image source, EPA

Ayatollah Khamenei's speech was similar in tone to his last Friday prayer sermon, delivered four years ago after top Iranian general Qasem Soleimani's assassination by the US and the subsequent missile attack by Iran on a US military base in Iraq, when there were fears of direct war against the US.

Khamenei tried to project strength to the outside world and calm to his domestic audience by delivering a major speech in the centre of Tehran in person, attempting to rebuff reports that he was afraid of appearing in public after the assassinations of Ismail Haniyeh and Hassan Nasrallah.

The sermon was also an attempt to project unity, with newly elected President Masoud Pezeshkian and other senior figures of the Iranian establishment all present. Pezeshkian was recently criticised by hardliners for suggesting Iran and Israel might end hostilities at some point.

He brushed aside any suggestion that Iran's support for its proxies in the region, which it calls the "Axis of Resistance" - would be impacted by Israel's recent operations.

He once again defended the 7 October attack by Hamas against Israel - something many other leaders of Muslim nations in the region have refused to do - and reiterated Iran will continue fighting against Israel through its proxies regardless of the killings of Haniyeh and Nasrallah.

Image source, Reuters

We've been following the various developments in the Middle East this morning - here are the key developments:

• A key road between Lebanon and Syria has been hit by an Israeli air strike. The Masnaa crossing was used by people fleeing Lebanon - many have been pictured walking near the crater this morning. Confirming the strike, the Israel Defense Forces (IDF) said it hit an underground tunnel being used by Hezbollah to store and transfer weapons
• Air strikes continued overnight in Lebanon, including near the airport in Beirut. At least 37 people have been killed in the last 24 hours, Lebanon said this morning. Separately, Iran's foreign minister landed at the airport this morning for a visit, according to Lebanese media
• Meanwhile, US media has cited Israeli officials as saying that the cousin of former Hezbollah leader Hassan Nasrallah, Hashem Safieddine, is thought to have been a target during last night's strikes. Safieddine is widely considered to be a possible successor to Nasrallah. Hezbollah has not yet commented
• Rockets have continued to be fired into Israel from Lebanon, Israel says - with the IDF saying around 20 rocket launches were identified this morning. Most were intercepted, it says, and the rest fell in open area
• Sirens sounded in southern Israel for first time approximately two months, the IDF also said
• In Iran, the supreme leader has led Friday prayers in Tehran for the first time in nearly five years. Ayatollah Ali Khamenei called Tuesday's attack on Israel "minimum punishment" and emphasised the "unity" of Muslims

Air raid sirens are currently sounding in southern Israel for the first time in approximately two months, the Israel Defense Forces (IDF) says.

"Almost a year after 7 October, Hamas is still threatening our civilians with their terrorism and we will continue operating against them," it adds, without providing further detail.

For context: Israeli forces launched a campaign to destroy the Hamas group in Gaza in response to its attack on southern Israel on 7 October 2023, in which about 1,200 people were killed and 251 others were taken back to Gaza as hostages.

More than 41,000 people have been killed in Gaza since then, according to the territory's Hamas-run health ministry.

A BBC team were filming on the Israeli side of Israel-Lebanon border, close to where clashes have been reported between Hezbollah and Israeli forces.

After hearing small arms fire and rockets from across the border, Middle East correspondent Lucy Williamson and her team ran for cover as warning sirens sounded.

The Israel Defense Forces has just confirmed attacks on an underground tunnel that crosses from Lebanon to Syria.

It follows reports earlier in the day that a road near the border crossing between the two countries had been hit in an air strike.

Now, posting on X, the IDF says the tunnel was "attacked" by Israeli Air Force fighter jets.

It says the tunnel was being used by Hezbollah to transfer and store weapons.

The Israeli military adds that infrastructure, military buildings and weapons depots were also hit.

Lina Sinjab
Middle East correspondent, in Beirut

Image source, Reuters

Hashem Safieddine, considered to be a potential successor of late Hezbollah leader Hassan Nasrallah, heads the executive council and is said to be part of the jihad council, which is in charge of leading and organising military and security activities.

Safieddine - a relative of late Hezbollah leader Hassan Nasrallah - is widely seen as attempting to fill big shoes that he is not fit for.

His look, body language and even the way he speaks mimics Nasrallah.

But both supporters and opponents of Nasrallah felt he was a charismatic leader, eloquent speaker who kept people glued to the screens whenever he spoke - something that Safieddine does not have, no matter how he tries.

It is still not confirmed if Safieddine would be the one to rule Hezbollah after Nasrallah. He is not top in the command chain and even within the group, there are views that he is not the best candidate to lead.

Hezbollah is being very careful on making any public announcement of who would be steering the wheel, as it is felt that Israel’s campaign is not just to weaken the group, but eliminate its power and any potential leadership.

But the view here is that Israel's aggression will create a cluster of "armed resistance" in Lebanon to retaliate.

Targeting of potential Hezbollah successor 'a watershed moment'published at 11:40 British Summer Time 4 October

11:40 BST 4 October

Joel Gunter
Reporting from Beirut

Image source, Reuters

The heavy air strikes that pounded Beirut last night reportedly targeted Hashem Safieddine - cousin and presumed successor to the assassinated Hezbollah leader, Hassan Nasrallah.

Israeli officials told the New York Times that Safieddine was attending a meeting of senior Hezbollah leaders in a bunker under Dahieh – the neighbourhood where Nasrallah was killed in a similar strike a week ago.

Convening a senior leadership meeting in the neighbourhood, after Israel has repeatedly demonstrated its ability and willingness to strike there, would seem like a huge risk. But the group likely does not have better options, says David Wood, senior Lebanon analyst for the International Crisis Group.

"To explain it you need to look back to the attacks on Hezbollah’s pagers," he says. "Combined with Israel’s exceptional intelligence penetration of the group, that means Hezbollah leaders need to have more face-to-face meetings, and where else can they really go but Dahieh?"

The neighbourhood is known to have deep Hezbollah bunkers underneath it. But those bunkers were put in place at a time when Hezbollah believed there was sufficient deterrence from Israel striking its senior leadership. "That deterrence has evaporated," Wood says.

There has been no official confirmation that Safieddine was targeted. But the significance of this moment was not in "taking out one Hezbollah leader or another", Wood says, it was in "taking so many leaders out at once. That’s what makes this a real watershed moment for Hezbollah as an organisation."

Israel's military says it killed Hezbollah communications commander, Muhammad Rashid Skafi, in strikes on Beirut yesterday.

In a statement, the Israel Defense Forces say Skafi had been in Hezbollah since 2000, and was close to senior leaders of the group.

Hezbollah has not commented.

A closer look at the crater damage near Syria’s border crossingpublished at 11:15 British Summer Time 4 October

11:15 BST 4 October

By Paul Brown

Footage from near Lebanon's border crossing with Syria, which has been verified by BBC Verify, shows a deep crater that spans the entire width of the road, rendering it impassable for vehicles.

To verify the footage, the team matched it to a video posted on YouTube in 2022, which was filmed by a motorcyclist using the road. The same pylons, trees and rock formations can be seen in footage of the damage.

Image source, X/Google Earth

We then cross-checked the location with tools that visualise terrain, which confirmed the area of the strike is around 700 meters from the checkpoint on the Lebanese side, external and around 5kms from the border itself.

A very similar location was struck nine years ago, so to confirm that the footage was new the team took stills from the video and searched for previous videos online. We also cross-referenced the video with the older footage to check for differences.

Sally Nabil
BBC Arabic correspondent, in Beirut

Many residents of Beirut’s southern suburb of Dahieh have already left home because of the heavy Israeli bombardment, which has been going on for days.

They made it to the centre of the Lebanese capital, but some are too poor to rent a place, while others could hardly find room in the busy displacement centres. So, they are staying out in the streets.

Najat tells me she’s sent her only child, Haider, 20, to Syria for safety. She is not sure if he will be safe over there.

"I found a lot of people from our neighbourhood heading for Syria, so I sent him with them," she adds.

Her story is a total reversal of what happened over a decade ago, when a huge number of Syrians, crossed into neighbouring Lebanon, to flee the conflict at home.

Her neighbour, Shadia, says her apartment in Dahieh used to "shake because of the Israeli air strikes".

"We were too scared to sleep," she says.

As we've been reporting, a key road connecting Lebanon to neighbouring Syria has been severely damaged by an Israeli strike.

Footage we've verified below shows the extent of the damage:

The Israeli military accused Hezbollah of using the crossing to transport military equipment into Lebanon.

The UN estimates 130,000 people have fled into Syria since 23 September.

Ghoncheh Habibiazad
BBC Monitoring

Khamenei praises Iran’s attack on Israel on Tuesday, and calling it completely “legal”.

He says what they did was the “minimum punishment” for Israel against their “astonishing crimes”.

He calls Israel a “vampire” regime and the US a “rabid dog” in the region. He says the Islamic Republic will carry out “any related duties” against Israel with “strength and fortitude”.

He emphasises twice that Iran will not “hesitate” nor “procrastinate” when it comes to Israel.

Ghoncheh Habibiazad
BBC Monitoring

Iranian Supreme Leader Ayatollah Ali Khamenei, in a rare appearance, is currently delivering a sermon at Tehran’s Imam Khomeini Mosalla Mosque.

In his first part of speech, which he delivered in Persian, he emphasised the “unity” of Muslims around the world based on the principles of the Islamic holy book, Quran.

He said Iran’s enemy is the same as the enemy of a Palestinian state, Lebanon and other Muslim nations.

Khamenei formally holds the title of Tehran Friday prayer leader, but usually assigns the sermons to a rotating cast of subordinates.

Iranian media reported today that will deliver a part of his speech in Arabic, addressing Lebanese and Palestinians.

The leader's sermons come three days before the first anniversary of the Hamas attacks on Israel that triggered the current regional war.

It also comes three days after Iran launched a missile barrage against Israel in retaliation for the killings of Hezbollah Leader Hassan Nasrallah and IRGC (Islamic Revolutionary Guard Corps) commander Abbas Nilforoushan, as well as that of Hamas leader Ismail Haniyeh in Tehran in July.

The last time Khamenei delivered his Friday prayer was shortly after Iranian General Qasem Soleimani died in a US drone attack near Baghdad's airport in 2020 and subsequent Iran's attack on US military bases in Iraq. The last time before that was in 2012.