Beirut: Israeli jets flew low over the city of Saida in southern Lebanon on Sunday causing sonic booms that broke windows and shook buildings for the first time in years, security sources and residents said.

Israeli warplanes regularly enter Lebanese airspace, the Lebanese military says, but rarely fly so low.

The Israeli military gave no immediate comment.

The sonic booms also caused panic in Saida, residents said.

Tension has risen between Lebanon’s Shiite group Hezbollah and Israel, which last fought a war in 2006.

Hezbollah has played down the prospects of another imminent conflict but warned it could take place on Israeli territory, and said its rockets could hit targets anywhere in Israel.

Israel’s air force chief has said it would use all its strength in a future war with Hezbollah.

The 2006 war killed 1,200 Lebanese, mostly civilians, and 160 Israelis, mostly soldiers.

Israeli politicians and generals have spoken often of an intention to hit hard in Lebanon if war breaks out, in an apparent bid to deter Hezbollah.

Major-General Amir Eshel said in 2014 that another conflict could see Israeli attacks 15 times more devastating for Lebanon than in 2006.

But at the conference, Eshel noted that “many elements busy achieving their goals” in Syria’s civil war were interested in preventing any fresh hostilities in Lebanon, where Israel says Hezbollah has built up an arsenal of more than 100,000 rockets.

Since early in the six-year-old Syria war, Hezbollah’s energies have been focused on propping up President Bashar Al Assad in alliance with Iran and Russia, throwing thousands of its fighters into battle against Syrian rebels.

On Thursday, Israeli warplanes struck a military position near the Mediterranean coast in western Syria early on Sunday.

The air strike targeted a facility near the town of Masyaf that some said was tied to Syria’s chemical weapons programme, in a stronghold of President Bashar Al Assad that is also heavily protected by the Russians.

Yaakov Amidror, Israel’s former national security adviser and a former general, said the strike targeted a weapons development and manufacturing site that was producing arms for Hezbollah.

Former Israeli military intelligence chief Amos Yadlin wrote on Twitter that the facility reportedly struck by Israel produces precision missiles, chemical weapons and barrel bombs.

Such a strike is “exceptional,” he said, and shows that “Israel won’t allow the stockpiling and production of strategic arms.”

In 2013, Syria said Israeli warplanes carried out an air raid on a scientific research centre in the Damascus suburb of Jamraya.

While largely staying out of the Syrian civil war, Israel has carried out a number of air strikes against suspected arms shipments believed to be bound for Lebanon’s Hezbollah militant group.