Smoke billows over a Lebanese village earlier this week amid ongoing cross-border hostilities between Israel and Hezbollah AFP

Israel and Hezbollah traded fresh cross-border fire, as fears of a regional conflict grew after Israel revealed it had approved plans for a Lebanon offensive and the Iran-backed militants vowed to blanket their foe in rockets.

Hezbollah said it fired dozens of rockets into northern Israel Thursday in retaliation for a deadly air strike in south Lebanon that Israel said killed one of the group's operatives. Hezbollah also claimed several other attacks on Israeli troops and positions over the course of the day.

The Israeli military said its jets had struck two weapons storage facilities and several other sites belonging to the group, and that it had fired artillery "to remove threats in multiple areas in southern Lebanon".

Just before midnight, the army said it had "successfully intercepted a suspicious aerial target that crossed from Lebanon".

And early Friday, Lebanese media reported fresh Israeli strikes in the country's south.

Experts are divided on the prospect of a wider war, almost nine months into Israel's campaign to eradicate Hezbollah's ally Hamas, the Palestinian militant group in the Gaza Strip.

Hezbollah and Israeli forces have exchanged near-daily fire since Hamas's October 7 attack on southern Israel triggered the Gaza war, and the bellicose talk has escalated along with the strikes.

Israel's main military backer the United States has sought to discourage any expansion of hostilities along the border.

In a meeting with visiting Israeli officials in Washington, Secretary of State Antony Blinken underscored "the importance of avoiding further escalation in Lebanon and reaching a diplomatic resolution that allows Israeli and Lebanese families to return to their homes", according to a statement.

In a televised address on Wednesday, Hezbollah chief Hassan Nasrallah had warned "no place" in Israel would "be spared our rockets" if a wider war began.

He also threatened nearby Cyprus if it opened its airports or bases to Israel "to target Lebanon".

European Union member Cyprus houses two British bases, including an airbase, but they are in sovereign British territory and not controlled by the Cypriot government.

On Thursday, Cyprus government spokesman Konstantinos Letymbiotis dismissed as "totally groundless" any suggestion of possible involvement in a conflict related to Lebanon.

Warplanes from the British airbase in Cyprus have, along with US forces, attacked Yemen's Iran-backed Huthi rebels who have for months been targeting Red Sea shipping.

On Thursday the US military said it had destroyed several Huthi drones, a day after its forces struck two rebel sites in Yemen.

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

The militants also seized hostages, 116 of whom remain in Gaza although the army says 41 are dead.

Israel's retaliatory offensive in Gaza has killed at least 37,431 people, also mostly civilians, according to the health ministry in the Hamas-ruled territory.

The latest toll on Thursday included at least 35 deaths over the previous day, the ministry said.

The Huthis and Hezbollah both say they are acting in response to Israel's actions in Gaza.

On Tuesday, Israel's military announced that "operational plans for an offensive in Lebanon were approved and validated".

The same day, Hezbollah published a video showing drone footage it purportedly recorded over northern Israel, including parts of Haifa's city and port.

US envoy Amos Hochstein on a trip to the region called for "urgent" de-escalation, while the UN special coordinator for Lebanon Jeanine Hennis-Plasschaert said there was "no inevitability to conflict" as she visited UN peacekeepers in the country's south.

The cross-border violence has killed at least 479 people in Lebanon, most of them fighters but also 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.

Weary residents of Beirut on Thursday downplayed the chances of war in Lebanon, which political deadlock has left essentially leaderless while a five-year economic meltdown continues.

In Israel, some citizens called for action against Hezbollah, and Noam Galili, 29, said: "I know what it is like to live close to Lebanon, but it never felt as dangerous as it does now."

The violence has already displaced tens of thousands of people, mostly in Lebanon, but also in northern Israel.

In southern Gaza, a United Nations mission found hundreds of thousands of displaced people "suffer from poor access to shelter, health, food, water and sanitation", a UN report said late Wednesday.

In central Gaza, residents said they had turned to cooking oil to power their cars.

US President Joe Biden has called for the implementation of a ceasefire plan he outlined last month.

Hochstein and Blinken say a deal to curb fighting in Gaza would by extension help resolve the Hezbollah-Israel violence.

But Israeli Prime Minister Benjamin Netanyahu's far-right coalition partners strongly oppose a Gaza ceasefire.

Netanyahu is also facing regular street protests demanding a deal to free the hostages and accusing him of prolonging the war.

"We will not leave the Gaza Strip until all of the hostages return," Netanyahu said Thursday to relatives of hostages killed in the territory.

"We do not have the option of giving up."

In a separate statement, he called the war a battle for Israel's existence.

But the viability of the war's stated goal of eradicating Hamas has been questioned in some corners.

Israeli military spokesman Rear Admiral Daniel Hagari told Israel's Channel 13 on Wednesday: "To say that we are going to make Hamas disappear is to throw sand in people's eyes. If we don't provide an alternative, in the end, we will have Hamas."

Blinken last month said Washington had not seen an Israeli post-war plan, adding "the trajectory Israel is on" would still leave thousands of Hamas fighters.

Israeli government spokesman David Mencer said Thursday that Hamas's "final stronghold" in Rafah on the border with Egypt was systematically being taken apart.

"And we will win," he told a press briefing.