Israel has said it carried out a wave of pre-emptive strikes across southern Lebanon to thwart a large-scale rocket and drone attack by Hezbollah.

The Israeli military said fighter jets destroyed thousands of the Iran-backed armed group’s rocket launchers on Sunday morning. Hezbollah and its ally, the Amal movement, said three fighters were killed.

Hezbollah said it still managed to fire 320 rockets and drones at Israel in retaliation for the assassination of a senior commander. Israel’s military said an Israeli navy soldier was killed.

The exchange was a major escalation after 10 months of hostilities that have raised fears of an all-out war.

There have been almost daily exchanges of fire across the Israel-Lebanon border since the day after the start of the war between Israel and Hamas in Gaza on 7 October.

Hezbollah has said it is acting in support of the Palestinian group, which is also backed by Iran. Both Hamas and Hezbollah are proscribed as terrorist organisations by Israel, the UK and other countries.

Since October, more than 560 people have been reported killed by Lebanon’s health ministry, the vast majority of them Hezbollah fighters, while 26 civilians and 23 soldiers have been killed in Israel, according to authorities.

The UN says almost 200,000 people have also been displaced on both sides of the border.

Israel’s attack on Hezbollah at around 04:30 (01:30 GMT) on Sunday was its biggest since the full-scale war between them in 2006.

The Israel Defence Forces (IDF) said about 100 fighter jets “struck and destroyed thousands of Hezbollah rocket launcher barrels” in more than 40 areas of southern Lebanon.

Spokesman Rear Admiral Daniel Hagari said it launched the strikes after identifying “extensive preparation” for a large-scale aerial attack by Hezbollah.

Lebanon’s state-run National News Agency reported that Israeli aircraft had struck Beaufort Castle, the Bir Kalb area, and the outskirts of the towns of Ain Qana, Kfar Fila, Louaizeh, Bsalia, Kfar Melki, Sajd and Sarba.