BEIRUT: Hezbollah on Wednesday said all of Israel would not be spared in the event of war, after Israel said it had approved a plan for a Lebanon offensive, stoking fears that the Gaza war will spread.

Hezbollah chief Hassan Nasrallah said "no place" in Israel would "be spared our rockets", in a televised address broadcast amid spiralling tensions across the Israel-Lebanon border.

Nasrallah - whose powerful Iran-backed group has exchanged near-daily fire with Israel since its ally Hamas's October 7 attack - also threatened the nearby island nation of Cyprus if it opened its airports or bases to Israel "to target Lebanon".

The Mediterranean island is home to two British military bases including an airbase, but they are in sovereign British territory and are not controlled by the Cypriot government.

Meanwhile, the war between Israel and Hamas raged in Gaza, with Israeli air strikes and clashes between troops and Palestinian fighters.

Witnesses and the civil defence agency in the Hamas-run Gaza Strip reported Israeli bombardment in western Rafah, where medics said drone strikes and shelling killed at least seven people.

And medics at the European hospital in Khan Yunis told AFP that 10 bodies were brought to the facility after a group of people were killed by an Israeli air strike on Salah al-Din road, east of Rafah city, as they waited for aid trucks to arrive.

The war has spilled across the region, drawing in a number of Iran-backed groups acting in solidarity with Palestinians in Gaza.

Fears that Israel might launch a full-blown war in Lebanon have spiked, with the Israeli military on Tuesday announcing that "operational plans for an offensive in Lebanon were approved and validated".

On Wednesday, Israel said its warplanes had struck Hezbollah sites in southern Lebanon overnight, while reporting a drone had infiltrated near the border town of Metula and targeted troops in an attack claimed by Hezbollah.

Hezbollah, meanwhile, announced the death of four of its fighters.

Lebanon's official National News Agency reported Israeli strikes on several areas in south Lebanon on Wednesday morning, including on the border village of Khiam, where an AFP photographer saw a large cloud of smoke.

Hezbollah later said it had fired "dozens of Katyusha rockets and artillery rounds" towards a barracks in Kiryat Shmona in northern Israel in retaliation for the attacks.

Israel said the Hezbollah attack did not cause any casualties and that its own "artillery struck the sources of fire".

The day before, the Islamist group released a more than nine-minute video showing aerial footage purportedly taken over northern Israel, including what it said were sensitive military, defence and energy facilities and infrastructure in the city and port of Haifa.

Speaking on a visit to troops on the northern border, Israel's military chief Lieutenant General Herzi Halevi said the video showed "a capability that we knew about" and that Israel was "creating solutions to deal with".

"We of course have infinitely greater capabilities," he added.

The Israeli army's announcement that its plans for an offensive in Lebanon had been approved, along with a warning from Foreign Minister Israel Katz of Hezbollah's destruction in a "total war", came as US envoy Amos Hochstein visited the region to push for de-escalation.

Hochstein returned to Israel on Tuesday evening for more talks with Prime Minister Benjamin Netanyahu after a series of meetings in Lebanon, according to an Israeli official.

Former Israeli security officials were split on the significance of the approval, with one telling AFP there would be an operation in Lebanon "within a few weeks" while another said the government was "more interested in a ceasefire".

The cross-border violence has killed at least 478 people in Lebanon, most of them fighters but also including 93 civilians, according to an AFP tally.

Israeli authorities say at least 15 soldiers and 11 civilians have been killed in the country's north.

Syrian state media said an Israeli strike on military sites in the country's south killed an army officer on Wednesday.

Israel has not commented on the report.

The Israel-Lebanon escalation comes as more than eight months of war have led to dire humanitarian conditions in Gaza and repeated UN warnings of famine.

UN deputy spokesman Farhan Haq told reporters that in recent weeks, there had been "an improvement" in aid reaching northern Gaza "but a drastic deterioration in the south".

While the humanitarian situation remains dire, fighting in the Gaza Strip continued.

Islamic Jihad, a Palestinian armed group that has fought alongside Hamas, said its militants were battling troops amid Israeli shelling of western Rafah.

The October 7 attack that triggered the war resulted in the deaths of 1,194 people, mostly civilians, according to an AFP tally based on Israeli official figures.

The group also seized 251 hostages. Of these, 116 remain in Gaza, although the army says 41 are dead.

Israel's retaliatory offensive has killed at least 37,396 people in Gaza, also mostly civilians, according to the territory's health ministry.

In a message on the occasion of the Muslim holiday of Eid al-Adha, US President Joe Biden called for the implementation of a ceasefire plan he outlined last month.

Hochstein said the plan would ultimately lead to "the end of the conflict in Gaza", which would in turn quell fighting between Israel and Hezbollah.

But US, Qatari and Egyptian mediation efforts have stalled for months since a one-week truce in November.

A UN report issued Wednesday detailed six "indiscriminate and disproportionate" Israeli strikes that killed at least 218 people in the first two months of the war.

 - AFP