Israel began a third day of strikes in southern Lebanon on Wednesday, hours after Hezbollah confirmed the death of a senior commander in an airstrike on Beirut, and a Lebanese minister said only Washington could help end the fighting. Lebanese media reported that Israeli airstrikes had targeted several areas in the country’s south, beginning at around 5 am, causing unspecified casualties.

Hezbollah meanwhile said it had launched a rocket targeting Mossad headquarters near Tel Aviv. Sirens had sounded in the Israeli city early on Wednesday, sending residents into bomb shelters. However, the Israeli military later said it had intercepted the missile, and no casualties or damage were reported. 

Earlier on Wednesday, Hezbollah had confirmed that senior commander Ibrahim Qubaisi was among six people killed by an Israeli airstrike on an apartment block in the Lebanese capital, Beirut, on Tuesday, as Israel had claimed earlier. Israel said Qubaisi headed the group’s missile and rocket force.

Israel’s offensive since Monday morning has killed 569 people, including 50 children, and wounded 1,835 in Lebanon, health minister Firass Abiad said reporters. Tuesday’s attacks came after Monday’s barrages racked up the highest death toll in any single day in Lebanon since the 15-year civil war that started in 1975.

Israel’s new offensive against Hezbollah has stoked fears that nearly a year of conflict between Israel and the militant Palestinian group Hamas in Gaza is escalating and could destabilize the Middle East. Britain urged its nationals to leave Lebanon and said it was moving 700 troops to Cyprus to help its citizens evacuate.

The UN Security Council said it would meet on Wednesday to discuss the conflict.“Lebanon is on the brink. The people of Lebanon – the people of Israel – and the people of the world – cannot afford Lebanon to become another Gaza,” UN Secretary-General António Guterres said.

At the UN, which is holding its general assembly this week, US President Joe Biden made a plea for calm. “Full-scale war is not in anyone’s interest. Even if a situation has escalated, a diplomatic solution is still possible,” he said.

Lebanon’s foreign minister Abdallah Bou Habib criticized Biden’s address as “not strong, not promising” and said the US was the only country “that can make a difference in the Middle East and about Lebanon.” Washington is Israel’s longtime ally and biggest arms supplier.

The US “is the key … to our salvation,” he told an event hosted by the Carnegie Endowment for International Peace in New York City. Bou Habib said that up to half a million people are estimated to have been displaced in Lebanon. He said Lebanon’s prime minister hoped to meet with US officials over the next two days.

In Lebanon, displaced families slept in shelters hastily set up in schools in Beirut and the coastal city of Sidon. With hotels quickly booked to capacity or rooms priced beyond the means of many families, those who did not find shelter slept in their cars, parks, or along the seaside.

Fatima Chehab came with her three daughters from Nabatieh and said her family had been displaced twice quickly. Hezbollah said it launched rockets at the Dado military base in northern Israel and attacked the Atlit naval base south of Haifa with drones, among other targets. An Israeli military spokesperson said six soldiers and civilians had been injured, most not seriously.

Suspected Israeli missiles were also launched at the Syrian port city of Tartous and were intercepted by Syrian air defenses, Syrian army sources said. The Israeli military declined to comment on the report.

Since the Gaza war started in October, Israel has intensified a years-long air campaign targeting Iran-aligned armed groups and their weapons transfers in Syria. Funerals were held on Tuesday for people killed in Lebanon by Israel’s bombardment. In the coastal city of Saksakiyeh, Mohammed Helal was defiant as he mourned his daughter Jouri.