David Lammy chaired a Cobra meeting to discuss preparations to evacuate remaining Britons from Lebanon, having already urged UK nationals to leave the country amid hostilities with Israel.

The foreign secretary led meetings in Whitehall on Friday as officials try to avoid a repeat of the chaos in which British people scrambled to leave Afghanistan when the Taliban took over in 2021.

There is no order to evacuate citizens yet, but fears of an all-out war are growing after an escalation of Israeli air strikes and targeted attacks on Hezbollah militants with exploding devices.

Lammy expressed concern about “rising tensions and civilian casualties” in Lebanon after strikes on Hezbollah targets in the south of the country on Thursday.

He repeated the Foreign Office’s warning to British nationals, urging them to leave Lebanon “while commercial options remain”, as the situation “could deteriorate rapidly”.

Hezbollah’s leader, Hassan Nasrallah, has vowed to retaliate after the attacks that targeted Lebanese militants with exploding pagers, killing and injuring many people.

On Thursday evening, Lammy said he had spoken to the Lebanese prime minister, Najib Mikati, and “expressed my deep concern over rising tensions and civilian casualties in Lebanon”.

He said that they had discussed “the need for a negotiated solution to restore stability and security” across the border between Israel and Lebanon.

Ministry of Defence insiders said no order had been given to organise an evacuation of the 16,000 or so British nationals in Lebanon but they said that plans were being sharpened this week, in response to the deteriorating situation.

The decision not to do so indicates that Israel has not told the UK it is planning a significant intensification of military action against Hezbollah, even allowing for the exploding pager and walkie talkie attacks widely attributed to its security agencies.

Military personnel and Foreign Office officials were deployed in early August as as part of preparatory planning for a range of possible conflict scenarios. These were being revised and updated this week, defence sources added.

Several European operators suspended flights in and out of Beirut and Tel Aviv this week and the only direct flights available out of the country, according to the flight comparison site Skyscanner, are with the Lebanese carrier Middle East Airlines.

Military transport planes could be made available if there are no commercial flights, such as the A400M Atlas or the C17 Globemaster. Chinook twin engine helicopters could also be used to evacuate smaller numbers in a hurry. The RAF base at Akrotiri in Cyprus would be the hub of any air evacuation effort.

The first choice of evacuation point would be Beirut’s international airport given the quality of the facilities, although it could prove problematic if there is a major outbreak of fighting, rendering the facility unsafe. The 2021 evacuation of Afghanistan used Kabul’s main airport, although evacuations from Sudan in April 2023 were done via an airbase near Khartoum.

Israeli warplanes carried out dozens of strikes across southern Lebanon late on Thursday, hours after Nasrallah threatened “tough retribution and just punishment” for the wave of attacks that targeted the organisation with explosives hidden in pagers and walkie-talkies.

The Israeli military said it had hit hundreds of rocket launchers that it said were about to be used “in the immediate future”.

The bombardment included more than 52 strikes across southern Lebanon, the Lebanese state news agency NNA said. Three Lebanese security sources told the Reuters news agency that they were the heaviest aerial strikes since the conflict began in October.

The hostilities between Israel and Hezbollah followed Hamas’s attack on Israel on 7 October, and Israel’s subsequent war on Gaza. Both Hamas and Hezbollah are backed by Iran.

A FCDO spokesperson said: “The foreign secretary has chaired a meeting of COBR this morning on the latest situation in Lebanon and to discuss ongoing preparedness work, with the risk of escalation remaining high.

“The safety of British nationals is our number one priority which is why we’re continuing to advise people to leave Lebanon now while commercial routes remain available.”