In pictures: Reaction to Hassan Nasrallah's deathpublished at 19:07 British Summer Time
The killing of Hezbollah's leader has sent shockwaves through the region.
Here's some photos of the reaction.
Hezbollah has confirmed the death of its leader Hassan Nasrallah after Israeli strikes on Beirut
Nasrallah, who had not been seen in public for years because of fears of being assassinated by Israel, was one of the best known and most influential figures in the Middle East
His death will be viewed in Israel as a huge victory, but Iran’s supreme leader declares five days of mourning and says his death "will not go unavenged"
US President Joe Biden says his death is a "measure of justice for his many victims"
Israel and Hezbollah are continuing to launch strikes across the border, and Israel's military also says it intercepted a missile fired from the Houthis in Yemen
Lebanese officials say 11 people were killed and 108 injured in strikes on Friday in Beirut, with local officials saying that nearly 800 people have been killed in Israeli strikes in Lebanon since Monday
Edited by Jude Sheerin, with Orla Guerin, Nafiseh Kohnavard & Hugo Bachega reporting from Beirut
The killing of Hezbollah's leader has sent shockwaves through the region.
Here's some photos of the reaction.
Some more comments from Joe Biden.
He says Israel's strike that killed the Hezbollah leader on Friday was in response to Nasrallah's decision to open up a "northern front" against Israel after Hamas’s attack from the south last 7 October.
“Ultimately, our aim is to de-escalate the ongoing conflicts in both Gaza and Lebanon through diplomatic means,” the US president says, adding that it's time for "the broader Middle East region to gain greater stability".
But Biden did not refer to a 21-day ceasefire plan between Israel and Hezbollah that he and US allies called for on Wednesday - an initiative that now seems in tatters.
He did signal that he hasn't given up hope of a ceasefire and hostage release deal for Gaza.
The UK government has reiterated calls for British people in Lebanon to leave the country on the "first available flight".
The Foreign Office says its advice remains that British citizens should register their presence.
"We know it's a distressing time for British nationals and all people in Lebanon, which is why we are doing everything we can to help," a spokesman said.
Carine Torbey
BBC Arabic correspondent, in Beirut
In many parts of the country, the Lebanese army is heavily deploying as fears of tension rise.
There are several factors that could threaten internal security. First, the sheer anger and feeling of loss for many supporters of Hezbollah who might take to the streets to express their fury at the killing of their leader by Israel.
But also, not everyone in the country is mourning the loss of Hasan Nasrallah and there’s increasing worry of provocations within the society pitting pro-Hezbollah and anti Hezbollah groups against each other.
This is the last thing Lebanon needs at the moment as Israel is relentlessly bombing parts of it, killing and injuring scores of people and displacing hundreds of thousands.
This fear seems to be widely shared as almost all political figures in the country have urged for national unity and warned against frictions.
The BBC's international correspondent Orla Guerin has been to a village close to the Israel-Lebanon border which was hit by an air strike in the early hours of Friday morning.
Press play to watch:
Biden's comments follow shortly after US Defence Secretary Lloyd Austin said the American military "remains postured to protect US forces and facilities in the region and committed to the defence of Israel".
The Pentagon said on Saturday morning that Austin had expressed full US support for Israel's right to defend itself in calls to his Israeli counterpart, Yoav Gallant, on Friday.
The defence secretary also said Washington was determined to prevent Iran from exploiting the situation in Lebanon", said Pentagon spokesman Maj Gen Pat Ryder.
US President Joe Biden has described Hassan Nasrallah's killing as a "measure of justice for his many victims".
He says these include "thousands of Americans, Israelis and Lebanese civilians".
Biden emphasises the US "fully supports" Israel's right to defend itself against Hezbollah, Hamas, the Houthis of Yemen and "any other Iranian-supported terrorist group".
The US president also says he has directed the Pentagon to enhance the defence posture of US military forces in the Middle East to "deter aggression".
A senior member of Hezbollah's intelligence has been killed in a military strike, Reuters news agency reports.
The Israeli military said it killed Hassan Khalil Yassin on Saturday in southern Beirut.
Ghoncheh Habibiazad
BBC Monitoring
More detail on Iranian Supreme Leader Ayatollah Ali Khamenei's comments.
He said the resistance front's attacks on "worn-out and declining" Israel will become "even more powerful".
Khamenei said Nasrallah was killed while "engaged in planning to defend the helpless people of the southern suburbs of Beirut and their destroyed homes, as well as the precious lives lost".
Iran's supreme leader said although the resistance front has lost an “outstanding standard-bearer” and Lebanon lost an “unparalleled leader”, Hezbollah will become stronger.
Khamenei also expressed condolences to Nasrallah’s family, to the resistance front and to the entire Islamic holy community.
Iran’s Supreme Leader, Ayatollah Ali Khamenei, has just declared five days of mourning for Hassan Nasrallah.
He said the Hezbollah chief's blood "will not go unavenged".
David Gritten
BBC News
As the conflict between Israel and Hezbollah intensifies, it carries with it the potential to draw in other Iran-backed forces in the Middle East.
As we just reported, both the Houthis in Yemen and Hamas in Gaza have recommitted their support for the Lebanese group in the wake of Hassan Nasrallah’s death.
An alliance of Iraqi Shia militias known as the Islamic Resistance in Iraq (IRI) has meanwhile claimed that it carried out several new drone attacks on Israel and the occupied Golan Heights.
All three are part of a wide network of Iran-backed armed groups operating in countries across the Middle East. They are opposed to Israel and the US, and sometimes refer to themselves as the “Axis of Resistance”, though the extent of Iran’s influence over them is not clear.
The US says co-ordination is overseen by Iran’s Islamic Revolutionary Guard Corps (IRGC) and its overseas arm, the Quds Force. Both are designated by the US as terrorist organisations, as are a number of the regional armed groups.
The groups have dramatically stepped up their attacks against Israel, US forces and other linked targets since the start of the war in Gaza in October, in what they say is a demonstration of their solidarity with the Palestinians.
Israeli and US-led forces have responded to some of those attacks with air strikes.
The Israel Defense Forces say they have just intercepted a missile "launched from Yemen".
In a post on X, the military says it stopped the incoming missile outside Israeli territory.
The Reuters news agency are reporting large bangs were heard.
For those of you less familiar with the geography of what we have been covering today, let's zoom out to give you some context on where Israel has been striking Hezbollah.
Lebanon shares most of its border with Syria and with northern Israel - where cross-border attacks have been occurring for years.
To the west is the Mediterranean Sea, which is where the capital city Beirut is located.
Now, let's zoom in a bit closer on Beirut and in particular focus on the southern suburbs of the capital where we know Israel has carried out a series of deadly strikes in recent days.
Dahieh, highlighted below, is a densely populated neighbourhood which is also a stronghold for Hezbollah.
It is also just north of Beirut's international airport.
Orla Guerin
BBC News, reporting from Beirut
Throughout the day, we have been driving through Dahieh, the Hezbollah stronghold in southern Beirut.
Black smoke could still be seen rising a few hours ago from one recent air strike.
Here and there, people were on the move carrying bags, apparently leaving the area.
The two busiest streets in Dahieh were largely deserted.
We spotted two Hezbollah members, with visible weapons, guarding one of the air strike locations.
Staying in Beiruit, let's turn to the humanitarian impact of Israel's latest strikes.
Photos are just coming through to us now, which show groups of people huddling in city squares who fled to the capital from Lebanon's south.
Carine Torbey
BBC Arabic correspondent, in Beirut
We were talking to some of the displaced in Ain al-Mraysseh, a neighbourhood in Beirut, when Hezbollah confirmed the killing of its leader Hassan Nasrallah.
Many could not handle the news.
Some collapsed on the floor, others started shouting, running in all directions and crying.
One lady said: “I wish they killed us all and kept him”.
Another said: “How could I ever go back to Dahieh knowing Sayyed [Hassan Nasrallah] isn’t there anymore”.
The shock is massive. Nasrallah wasn’t just the top leader for his large base of supporters - he was an idol.
Not everyone in Beirut is a Hezbollah supporter - but in some streets, people fired bullets in the air as a sign of anger and sadness.
In a recent update from Lebanon's health ministry, it says that 11 people were killed on Friday as a result of Israeli air strikes in southern Beirut.
Officials add that 108 people are known to have been injured.
In a separate update this afternoon, the ministry has set out a hotline specifically for cancer patients - saying they would be transferring those who are receiving radiotherapy to day treatment departments.
BBC Verify has been analysing footage of yesterday evening's strikes which are now known to have killed Hezbollah leader Hassan Nasrallah.
The sheer scale of the explosions ensured that there were numerous videos shot from multiple vantage points. These allowed us to triangulate the precise location.
One early clip, filmed from the runway of Beirut airport, showed several plumes of smoke rising from a distant location due north. While we could not confirm a precise location at such a distance, the footage confirmed that the strikes had taken place in a similar area to other Israeli strikes on southern Beirut over the previous week.
Another striking clip, filmed through a window, showed numerous explosions at much closer proximity.
Visible solar panels and the shape of nearby rooves were compared with publicly available satellite imagery to get a better sense of the location. The footage also confirmed that there were multiple strikes – which is vital information for assessing the extent of damage.
As the evening wore on, footage from the ground showed at least two buildings had collapsed close to a main road called Burj el-Brajne. There are reports that a number of other buildings were also destroyed, which we are seeking to confirm.
We also await fresh satellite imagery of the area which will give a much fuller assessment of the extent of the strikes.
Let's bring you some more comments from other countries and groups in the Middle East who have been reacting to the news of Hassan Nasrallah's death.
Jiyar Gol
BBC World Affairs correspondent
Iranian officials report that Abbas Nilforushan, the deputy commander of Iran's Islamic Revolution Guard Corps (IRGC) operations, was killed in yesterday's attack in Beirut.
As a reminder, Iran's Islamic Revolution Guard Corps (IRGC) was set up 40 years ago to defend the country's Islamic system, and to provide a counterweight to the regular armed forces.