"Infrastructure sites adjacent to the Masnaa border crossing between Syria and Lebanon were struck last night," the military said in a statement.

It said the air raids were aimed at preventing the flow of weapons into Lebanon from neighbouring Syria and included targeting an alleged underground tunnel used to move arms across the border.

Fighter jets "struck an underground tunnel crossing from the Lebanese border into Syria. The 3.5 kilometre (two mile) long tunnel enables the transfer and storage of large quantities of weapons underground," the military said.

"The tunnel's operations were led by the 4400 Unit, the unit responsible for the transportation of weapons from Iran and its proxies to Hezbollah in Lebanon."

Earlier, Lebanon said the Israeli strikes cut off the main international road to Syria.

The strikes come after 310,000 people, mostly Syrian refugees, crossed into Syria in recent days fleeing the war in Lebanon between Israel and Hezbollah.

Nearly a year after Palestinian militant group Hamas launched the deadliest attack on Israel in its history on October 7, Israel announced it was shifting its focus to securing its border with Lebanon.

Hezbollah started launching low-intensity strikes on Israel last October, in support of Hamas in Gaza, forcing some 60,000 Israelis to flee their homes in the north of the country.