Lebanon’s Hezbollah launched a big rocket and drone attack at Israel on Thursday and threatened to hit new targets in retaliation for the killing of a top commander, in the latest surge of violence in the steadily worsening conflict across the border.

Sparked by the Gaza war, the conflict between Iran-backed Hezbollah and Israel has been gradually intensifying for months, raising fears of a full-scale war, which both sides have indicated they want to avoid and diplomats are working to prevent.

As the latest violence played out in areas at or near the frontier — in keeping with the pattern of the last nine months — the sound of sonic booms rattled nerves for the second successive day in Beirut and other parts of Lebanon.

Israeli jets broke the sound barrier over several areas of the country, Lebanon’s National News Agency reported.

Hezbollah said it launched more than 200 rockets and a swarm of drones at 10 Israeli military sites in retaliation for Israel’s killing of Hezbollah commander Mohammed Nasser in the south on Wednesday. Nasser is one of the most senior Hezbollah commanders to be killed by Israel during the conflict.

The Israeli military said around “200 projectiles and over 20 suspicious aerial targets were identified crossing from Lebanon into Israeli territory”, a number of which were intercepted by Israeli air defences and fighter jets.

Israel’s ambulance service said no casualties were reported. The Israeli military said some of the drones and interceptor shrapnel set off fires.

The Israeli air force “struck Hezbollah military structures” in the areas of Ramyeh and Houla”, it said, referring to two villages in south Lebanon.

Senior Hezbollah official Hashem Safieddine, speaking at an event in Beirut commemorating Nasser, indicated his group would widen its targeting. “The series of responses continues in succession, and this series will continue to target new sites that the enemy did not imagine would be hit,” Safieddine said.

Diplomatic push

The US has been leading diplomatic efforts to deescalate the fighting. Hezbollah has said it will not cease fire as long as Israel continues its offensive in the Gaza Strip.

The hostilities have inflicted a heavy toll on both sides of the frontier, forcing tens of thousands of people to flee their homes.

Amos Hochstein, a senior US official discussed French and American efforts to restore calm in meetings with French officials on Wednesday, a White House official said. “France and the US share the goal of resolving the current conflict across the Blue Line by diplomatic means, allowing Israeli and Lebanese civilians to return home,” the official said.