Travelers waited in long lines at Beirut airport on Sunday, some after cutting summer holidays short, as airlines have cancelled flights and fears have grown of all-out war between Israel and Hezbollah.

"I'm not happy to leave. I wanted to spend the whole summer in Lebanon then go back to work" in France, said Joelle Sfeir from the crowded departures hall at Beirut airport.

But "my flight was cancelled and I was forced to book another ticket today," she told AFP.

"I cut my trip short so I could find a flight," she added.

Lebanon's Iran-backed Hezbollah movement has traded near-daily fire with Israeli forces in support of ally Hamas since the Palestinian militant group's October 7 attack on Israel triggered the Gaza war.

But the killing Wednesday of Hamas political leader Ismail Haniyeh in Tehran, hours after the Israeli assassination in Beirut of Hezbollah's military chief Fuad Shukr, has sparked vows of vengeance from Iran and other Tehran-backed armed groups, including Hezbollah, and sent regional tensions skyrocketing.

Several airlines including Lufthansa and Air France have delayed or suspended flights to Lebanon, and countries have issued urgent calls for foreign nationals to leave in recent days.

France did so Sunday, warning of "a highly volatile" situation, while the US embassy in Lebanon a day earlier urged its citizens to leave on "any ticket available".

- Reservations cancelled -

Fears have spiked that months of cross-border violence could degenerate into all-out conflict between Hezbollah and Israel, who last fought a devastating war in the summer of 2006.

Israel bombed Lebanon's only passenger airport in Beirut during that war.

Embassies have repeatedly urged their citizens to leave Lebanon while commercial flights are still available.

In the departures hall, families sat on metal seats, children lying in their parents' laps, while passengers watched over piles of bags and checked television screens for flight departures for locations including Istanbul, Amman and Cairo.

The tensions and cancellations have thrown travel plans into chaos for many Lebanese who work or study abroad and who usually use their annual summer holiday to visit relatives and friends back home.

Gretta Moukarzel, who runs a travel agency near Beirut, said she had "received a flood of calls from clients who want to leave and who fear being stuck in Lebanon".

Finding seats has been difficult because of the number of cancelled flights and the increased demand, particularly for European countries, she told AFP by telephone.

"A large number of Lebanese who were coming to Lebanon for the holiday have cancelled their reservations," she added.

- Flights postponed -

Passengers also waited in long queues at check-in booths and again to pass through security.

Sirine Hakim, 22, said she had spent almost three weeks in Lebanon to see family and had to leave due to work commitments abroad.

"I was supposed to depart yesterday, but my flight was postponed," she said.

Near the arrivals area, usually crowded during the summer season, just a small number of people were waiting for loved ones.

Along the airport road that passes through Beirut's southern suburbs, a Hezbollah stronghold, a huge billboard showed the images of Hamas's Haniyeh and Hezbollah's Shukr reading: "We will seek revenge".

The slain pair were pictured flanking Qasem Soleimani, an Iranian Revolutionary Guards commander and head of its foreign operations arm the Quds Force who was killed in a US drone strike in Iraq in 2020.

The cross-border violence since October has killed some 545 people in Lebanon, mostly fighters but also including 115 civilians, according to an AFP tally.

On the Israeli side, including the annexed Golan Heights, 22 soldiers and 24 civilians have been killed, according to army figures.

Lebanese on Sunday were also marking the fourth anniversary of a catastrophic explosion at Beirut port that killed more than 220 people, injured some 6,500 and devastated swathes of the capital.