BEIRUT, Lebanon, Sept 19, 2024 (BSS/AFP) - A second wave of device explosions killed 20 people and wounded more than 450 others on Wednesday in Hezbollah strongholds in Lebanon, officials said, stoking fears of an all-out war with Israel.

A source close to Hezbollah said walkie-talkies used by its members blew up in its Beirut stronghold, with state media reporting similar blasts in south and east Lebanon.

AFPTV footage showed people running for cover when an explosion went off during a funeral for Hezbollah militants in south Beirut in the afternoon.

"The wave of enemy explosions that targeted walkie talkies... killed 20 people and wounded more than 450," Lebanon's health ministry said in a statement.

They came a day after the simultaneous explosion of hundreds of paging devices used by Hezbollah killed 12 people, including two children, and wounded up to 2,800 others across Lebanon, in an unprecedented attack blamed on Israel.

There was no comment from Israel, which only hours before Tuesday's attacks had announced it was broadening the aims of its war with Hamas in Gaza to include its fight against the Palestinian group's ally Hezbollah.

"The centre of gravity is moving northward," Israeli Defence Minister Yoav Gallant said during a visit to an air base on Wednesday. "We are at the start of a new phase in the war."

Israeli officials have remained tight-lipped about the explosions that led the television news bulletins and dominated newspaper headlines.

Amos Harel of the left-leaning Haaretz newspaper said the pager and walkie-talkie blasts had put "Israel and Hezbollah on the brink of all-out war".

- US warns against escalation -

The White House warned all sides against "an escalation of any kind".

"We don't believe that the way to solve where we're at in this crisis is by additional military operations at all," US National Security Council spokesman John Kirby told reporters.

The Iran-backed Hezbollah has traded near-daily cross-border fire with Israeli forces since Palestinian militants attacked Israel on October 7, sparking the war in Gaza.

Lebanese Foreign Minister Abdallah Bou Habib warned that the "blatant assault on Lebanon's sovereignty and security" was a dangerous development that could "signal a wider war".

Hezbollah said Israel was "fully responsible for this criminal aggression" and vowed revenge.

The influx of so many casualties all at once overwhelmed hospitals in Hezbollah strongholds.

At a Beirut hospital, doctor Joelle Khadra said "the injuries were mainly to the eyes and hands, with finger amputations, shrapnel in the eyes -- some people lost their sight."

A doctor at another hospital in the Lebanese capital said he had worked through the night and that the injuries were "out of this world -- never seen anything like it".

- Heavy blow -

Analysts said operatives had likely planted explosives on the paging devices before they were delivered to Hezbollah.

"A small plastic explosive was almost certainly concealed alongside the battery, for remote detonation via a call or page," said Charles Lister of the Middle East Institute.

Among the dead was the 10-year-old daughter of a Hezbollah member, killed in east Lebanon's Bekaa Valley when her father's pager exploded, the family and a source close to the group said.

The attack dealt a heavy blow to Hezbollah, which already had concerns about the security of its communications after losing several key commanders to targeted air strikes in recent months.

The preliminary findings of a Lebanese investigation into the blasts found the pagers had been booby-trapped, a security official said.

"Data indicates the devices were pre-programmed to detonate and contained explosive materials planted next to the battery," the official said, requesting anonymity to discuss sensitive matters.

A source close to Hezbollah, asking not to be identified, said the pagers were "recently imported" and appeared to have been "sabotaged at source".

After The New York Times reported that the pagers had been ordered from Taiwanese manufacturer Gold Apollo, the company said they had been produced by its Hungarian partner BAC Consulting KFT.

A government spokesman in Budapest said the company was "a trading intermediary, with no manufacturing or operational site in Hungary".

As fears again surged of a regional conflagration nearly a year into the Gaza war, Lufthansa and Air France announced the suspension of flights to Tel Aviv, Tehran and Beirut until Thursday.

- 'Extremely volatile' -

Since October, the unabating exchanges of fire between Israeli troops and Hezbollah have killed hundreds of people, mostly fighters, in Lebanon, and dozens including soldiers on the Israeli side.

They have also forced tens of thousands of people on both sides of the border to flee their homes.

United Nations rights chief Volker Turk said Tuesday's attack had come at an "extremely volatile time", calling the blasts "shocking" and their impact on civilians "unacceptable".

UN chief Antonio Guterres urged governments "not to weaponise civilian objects".

Senior diplomats from the United States, Britain, Germany, France and Italy will meet on Thursday in Paris to discuss the spiralling tensions in the Middle East, sources said, ahead of a UN Security Council meeting planned for Friday.

The October 7 attack that sparked the war resulted in the deaths of 1,205 people, mostly civilians, on the Israeli side, according to an AFP tally based on official Israeli figures that include hostages killed in captivity.

Out of 251 hostages seized by militants, 97 are still held in Gaza, including 33 the Israeli military says are dead.

Israel's retaliatory military offensive has killed at least 41,272 people in Gaza, most of them civilians, according to data provided by the Hamas-run territory's health ministry. The UN has acknowledged these figures as reliable.

In Gaza on Wednesday, the civil defence agency said an Israeli air strike on a school-turned-shelter killed five people, while the Israeli military said it targeted Hamas militants.