The United Nations humanitarian chief has voiced alarm at the prospect of Israel's war against Hamas in Gaza spreading to Lebanon, warning that it was "potentially apocalyptic".
As the war in Gaza nears its tenth month, Israel's top ally - the United States - warned of the risk of a major conflict against the Iran-backed militant group Hezbollah in Lebanon, following an escalation in cross-border fire.
Israel's military said last week that plans for an offensive in Lebanon were "approved and validated", prompting fresh threats from Hezbollah chief Hassan Nasrallah.
UN humanitarian coordinator Martin Griffiths told reporters that he saw Lebanon as "the flashpoint beyond all flashpoints", pointing to southern Lebanon in particular.
Mr Griffiths said he had been discussing with colleagues in Jerusalem about the prospects of what might happen there.
"We are worried about the potential for further tragedy and deaths," he said.
"It's potentially apocalyptic."
Mr Griffiths, whose term finishes this week, warned that a war involving Lebanon "will draw in Syria ... it will draw in others".
And "it will of course have an impact on Gaza; of course it will have an impact on the West Bank. "It's very alarming," he said.
Five reported injured in Israeli strike on Lebanon
An Israeli strike wounded five people in the town of Nabatiyeh in southern Lebanon, state media reported.
The attack destroyed a two-storey building, the report said, adding the five people who were in the vicinity of the structure were taken to hospital.
There was no immediate comment from the Israeli military on the strike.
Israel carried out ten attacks on border regions today, Lebanon's national news agency said.
Hezbollah claimed six attacks against Israeli military positions in the border region.
Some 481 people have died in Lebanon as a result of the Israel-Hezbollah clashes since 7 October, including 94 civilians, according to a tally.
On the Israeli side, at least 15 soldiers and 11 civilians have been killed, according to Israel.
The bloodiest Gaza war started with Hamas' attack on southern Israel last October that resulted in the deaths of 1,195 people, mostly civilians, according to Israeli figures.
The militants also seized about 250 hostages, 116 of whom remain in Gaza, although the army says 42 are dead.
Israel's retaliatory offensive has killed at least 37,718 people, also mostly civilians, Gaza's health ministry has said.
Since the war began, "Gaza has taught us a new level of tragedy and cruelty", Mr Griffiths said.
"But we are all worried that it may only be the beginning."
He said the UN humanitarian agency OCHA and other aid agencies were preparing for a broader crisis.
"There is a lot of preparedness on the aid side," he said. But the kind of preparedness needed was "political", he stressed.
"The problem is stopping this war from getting worse."
