What is happening in the Israel-Lebanon crisis? The key developments

More than 550 people including 50 children have been killed in two days of Israeli airstrikes on Lebanon as fears of an all-out Middle East conflict grow.

A boy checks the damage to a building hit in an Israeli airstrike in the southern village of Akbieh, Lebanon, Tuesday, Sept. 24, 2024. (AP Photo/Mohammed Zaatari)
A boy checks the damage left by an Israeli airstrike in the southern village of Akbieh, Lebanon. (Alamy)

Thousands of people are fleeing southern Lebanon after two days of airstrikes that have left more than 550 people dead.

Israel has said it is attacking targets held by Hezbollah after more than a year of rocket fire between the country and the militant group since the 7 October attacks by Hamas, which triggered the war in nearby Gaza.

Herzi Halevi, Israel's military chief, said "the situation requires continued, intense action in all arenas" and that Iran-backed Hezbollah must not be given a break.

The Lebanese health minister Firass Abiad said 50 children and 94 women were among the hundreds killed, claiming that the "vast majority" of those killed on Monday were "unarmed people in their homes".

International leaders have expressed fears of the conflict on Israel's northern border snowballing into an all-out war, potentially involving Iran, with politicians at the United Nations General Assembly in New York on Tuesday eager to find a peaceful resolution.

Read a full breakdown of the key updates or click below to skip to each section

> New Israeli strikes on Lebanon after 558 killed

> ‘Tens of thousands’ have fled southern Lebanon

> Is this war? The Israeli-Hezbollah conflict is hard to define — or predict

> What is Hezbollah?

> A timeline of warfare on Israel-Lebanon border

Residents check the site of an Israeli airstrike in Beirut's southern suburbs, Tuesday, Sept. 24, 2024. (AP Photo/Hassan Ammar)
Residents check the site of an Israeli airstrike in Beirut's southern suburbs. (Alamy)

Israel's overnight strikes on southern Lebanon came after it said it had killed a "large number" of militants when it hit about 1,600 suspected Hezbollah targets around the country.

Hezbollah said Tuesday it had launched volleys of missiles at Israeli military bases, hours after 180 of its projectiles and an unmanned aerial vehicle crossed into Israeli airspace, sending people in the city of Haifa running for shelter.

In Lebanon, Monday's raids killed 558 people, including 50 children and 94 women, according to Health Minister Firass Abiad. "The vast majority, if not all of those killed in yesterday's attacks were unarmed people in their homes," he said.

Cars sit in traffic as they flee the southern villages amid ongoing Israeli airstrikes, in Sidon, Lebanon, Monday, Sept. 23, 2024. (AP Photo/Mohammed Zaatari)
Cars sit in traffic as they flee the southern villages of Lebanon. (Alamy)

"Tens of thousands" of people in Lebanon have fled their homes since Monday amid Israeli air strikes on Hezbollah targets in the south of the country, the UN refugee agency said on Tuesday. "We are gravely concerned about the serious escalation in the attacks that we saw yesterday," UN refugee agency spokesman Matthew Saltmarsh told reporters in Geneva.

"Tens of thousands of people were forced from their homes yesterday and overnight, and the numbers continue to grow," he said. "The toll on civilians is unacceptable."

Flames rise from an Israeli airstrike on Mahmoudieh mountain, as seen from Marjayoun town, south Lebanon, Tuesday, Sept. 24, 2024. (AP Photo/Hussein Malla)
Flames rise from an Israeli airstrike on Mahmoudieh mountain, as seen from Marjayoun town, southern Lebanon. (Alamy)

Israel is bombing targets across many parts of Lebanon, striking senior militants in Beirut and apparently hiding bombs in pagers and walkie-talkies. Hezbollah is firing rockets and drones deep into northern Israel, setting buildings and cars alight. But no one is calling it a war — not yet.

"If someone had told me ... in summer 2023 that Hezbollah is striking Israeli bases in Israel, and Israel is striking southern Lebanon and parts of southern Beirut, I would have said, OK, that’s an all-out war," said Andreas Krieg, a military analyst at King’s College London.

“I think the Israelis are trying to either tell Hezbollah, you come to the negotiation table and we’ll settle this through diplomacy, or we’ll push you into a corner until you overreact," Krieg said. “And that will be the all-out war.”

Hezbollah members carry the coffin of Hezbollah commander Ibrahim Akil during the funeral procession in Beirut's southern suburb, Sunday, Sept. 22, 2024. (AP Photo/Bilal Hussein)
Hezbollah members carry the coffin of commander Ibrahim Akil during a funeral procession in southern Beirut. (Alamy)

Hezbollah is a radical Shia Islamist paramilitary group based in Lebanon. Backed by Iran, it is considered to be the most powerful and heavily-armed non-state actor in the world.

Its leader, Hassan Nasrallah, has claimed that the group could field more than 100,000 trained fighters, although independent observers believe that this is more likely to be 20,000 to 50,000.

Hamas and Hezbollah are both Islamist groups committed to the destruction of Israel, but there are key differences and between them.

Qliyaa, Qlyiaa, Lebanon. 15th Sep, 2024. Heavy smoke billows following an Israeli air strike in the outskirts of the southern Lebanese border village of Mahmoudiyeh amid an ongoing cross the border clashes between Israeli troops and pro-Iranian Hezbollah fighters. (Credit Image: © Marwan Naamani/ZUMA Press Wire) EDITORIAL USAGE ONLY! Not for Commercial USAGE! Credit: ZUMA Press, Inc./Alamy Live News
Heavy smoke billows following an Israeli air strike in the outskirts of the southern Lebanese border village of Mahmoudiyeh. (Alamy)

Some 100,000 Palestinians who fled or were expelled from their homes in what had been British-ruled Palestine during the war arrive in Lebanon as refugees. Lebanon and Israel agree an armistice in 1949.

In 1973, disguised Israeli special forces shoot dead three Palestinian guerrilla leaders in Beirut in retaliation for the killing of Israeli athletes at the 1972 Munich Olympics.

Palestinian guerrilla raids into Israel and Israeli military reprisals on targets in Lebanon intensify during the 1970s, leading many Lebanese to flee the south and aggravating sectarian tensions inside Lebanon, where civil war is starting.