Israel said it launched "extensive" new strikes Tuesday against Lebanon's Hezbollah, after Lebanon said hundreds were killed the day before when clashes sparked by the almost year-long Gaza war intensified.
Lebanon said Israeli strikes killed at least 558 people on Monday, sending tensions soaring on the deadliest day of violence in the country since its 1975-90 civil war.
Lebanese Health Minister Firass Abiad, who gave Monday's toll of 558 dead, said the "vast majority, if not all, of those killed in yesterday's attacks were unarmed people in their homes".
His office said another six people were killed Tuesday in a strike on south Beirut.
Israel said it "eliminated" Hezbollah's rocket forces commander Ibrahim Kobeissi in the strike on the Lebanese capital. A source close to Hezbollah also said Kobeissi had been killed.
At the UN General Assembly in New York, United Nations Secretary-General Antonio Guterres warned the situation in Lebanon was critical.
"We should all be alarmed by the escalation. Lebanon is at the brink," he said, while cautioning against "the possibility of transforming Lebanon (into) another Gaza".
President Joe Biden of the United States, Israel's closest ally, warned against a full-blown war in Lebanon, in his speech during the New York gathering.
"Full-scale war is not in anyone's interest. Even though the situation has escalated, a diplomatic solution is still possible," Biden said.
Despite pressure mounting on Israel, Prime Minister Benjamin Netanyahu vowed to continue the withering air campaign in Lebanon.
Hezbollah said it launched volleys of missiles at Israeli military bases Tuesday, hours after firing 180 projectiles at Israel, sending people in the city of Haifa running for cover.
The Israeli military said more than 50 projectiles were fired from Lebanon in less than 10 minutes, adding it intercepted most of them and hit Hezbollah again.
Hezbollah said later it targeted four more Israeli military sites, including a camp south of Haifa, with "Fadi-3" rockets.
It said it fired another barrage of 90 rockets at a military base near the Galilee town of Safed.
The United Nations said tens of thousands of Lebanese had fled their homes because of the Israeli bombardment.
"Tens of thousands of people were forced from their homes yesterday and overnight, and the numbers continue to grow," said UN refugee agency spokesman Matthew Saltmarsh. "The toll on civilians is unacceptable."
The agency later said it was "outraged" after one of its staff members and a contractor were killed.
Thuraya Harb, a 41-year-old housewife at a makeshift centre for displaced families in Beirut, described Tuesday as a "day of terror".
"I didn't want to leave my home, but the children were scared," the mother of four said, adding that her family fled "with nothing but the clothes on our backs".
Not all the displaced stayed in Lebanon. A security official in neighbouring Syria told AFP about 500 people had crossed the border to flee the bombing.
Iran condemned the raids, with its president, Masoud Pezeshkian, saying its ally "cannot stand alone" against Israel.
"We must not allow Lebanon to become another Gaza at the hands of Israel," he said.
Other leaders have expressed alarm over the rapid escalation, with the European Union's top diplomat Josep Borrell warning "we are almost in a full-fledged war".
A US official, speaking on condition of anonymity, said Washington opposed an Israeli ground invasion targeting Hezbollah and had "concrete ideas" on how to de-escalate the crisis.
Israel's ambassador to the UN Danny Danon meanwhile said Israel was "not eager to start any ground invasion" in Lebanon.
Since the start of the Gaza war, clashes along the Lebanon-Israel border have forced tens of thousands of people on both sides to flee their homes.
The violence between Israel and Hezbollah escalated dramatically last week, when coordinated communications device blasts that the militants blamed on Israel killed 39 people and wounded almost 3,000.
Then on Friday, an Israeli strike on southern Beirut, a bastion of Hezbollah, killed its elite Radwan Force commander, Ibrahim Aqil.
Rescuers rush to the scene of an Israeli airstrike that targeted the southern Lebanese village of Abbasiyeh on Tuesday. AFP
Lebanese army soldiers and rescuers work in a street under a residential building whose top two floors were hit by an Israeli strike in the Ghobeiri area of Beirut's southern suburbs on Tuesday. AFP
People fleeing Israeli bombings in Lebanon prepare to cross the border with Syria through the Masnaa crossing is eastern Lebanon on Tuesday. AFP
Men walk past a hole in the ground and a burnt tractor after a rocket fired from southern Lebanon hit the town of Kfar Manda in northern Israel on Tuesday. AFP
Smoke billows after an Israeli airstrike that targeted the southern Lebanese village of Abbasiyeh on Tuesday. AFP
A woman sits with a child on her lap next to bags on the ground as people fleeing from Lebanon arrive on the Syrian side of the border with Lebanon in Jdeidat Yabus in southwestern Syria on Tuesday. AFP
