Britons have been urged to leave Lebanon amid warnings the country faces a humanitarian “catastrophe” following the latest round of Israeli air strikes.

On Friday, the Foreign Office warned that British nationals should “leave now” as series of massive explosions levelled multiple apartment buildings in Beirut.

In a statement, the Foreign Office said it was “working to increase capacity” and secure seats for British nationals on flights out of the country.

Friday’s strikes have been reported to be an attempt to kill Hassan Nasrallah, the leader of Lebanese militant group Hezbollah, and were followed by further strikes on southern Beirut overnight, prompting civilians to move north in an effort to find safety.

On Saturday, the Israeli government said it had killed Ms Nasrallah, with the Israeli Defence Forces posting on X, formerly Twitter, he would “no longer be able to terrorise the world”.

Ettie Higgins, Unicef’s deputy representative in Lebanon, said “thousands and thousands” of people had fled southern Beirut, while hospitals were “overwhelmed” and water pumping stations had been destroyed.

She told the BBC’s Today programme: “Even the most basic essential services of healthcare and water are now being rapidly, rapidly depleted.

“There was already a humanitarian crisis in Lebanon given that it’s been hosting over 1 million refugees from Syria for over a decade, so it’s rapidly escalating into a catastrophe.”

She added that 50 children had already been killed, and said she expected that figure to rise as the air strikes continued.

Flames rise after an Israeli airstrike in the southern suburbs of Beirut, Lebanon, Saturday, Sept. 28, 2024
Israeli air strikes targeted southern Beirut overnight (Hussein Malla/AP)

Israel has insisted the air strikes have targeted Hezbollah military installations or senior figures, with Friday’s attack said to have targeted the main Hezbollah headquarters.

The latest round of strikes will have further dampened hopes of an international ceasefire in the region, coming shortly after Israeli prime minister Benjamin Netanyahu promised his country’s campaign against Hezbollah would continue during an address to the UN.

Western governments have expressed concern that the intensified conflict between Israel and Iran-backed Hezbollah could trigger a wider regional war, with figures including Sir Keir Starmer and US President Joe Biden calling for a ceasefire.

Mideast In this Oct. 24, 2015 file photo, Hezbollah leader Sheik Hassan Nasrallah addresses a crowd during the holy day of Ashoura, in a southern suburb of Beirut, Lebanon
Friday’s air strike that levelled a number of apartment buildings in Lebanon was said to have been an attempt to kill Hezbollah leader Hassan Nasrallah (Hassan Ammar/AP)

In his own address to the UN on Thursday, the Prime Minister said: “I call on Israel and Hezbollah. Stop the violence. Step back from the brink.

“We need to see an immediate ceasefire to provide space for a diplomatic settlement and we are working with all partners to that end.”

The PA news agency understands the UK Government has successfully asked airlines to increase capacity on routes out of Lebanon, with Foreign Office teams in Beirut to support British consulate services.

It is thought they are ready to facilitate evacuations by sea or air, which could be triggered if the security environment degrades further and British nationals are no longer able to leave the Middle East through other routes.

Around 5,000 British citizens are in Lebanon, and the United Nations said 118,000 Lebanese people have been displaced in recent days.