Israeli air strikes and clashes between troops and Palestinian militants rocked Gaza on Wednesday, as Israel's army warned it had readied an "offensive" against the Lebanese Hezbollah movement on the country's northern front.

The 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 U.S. envoy Amos Hochstein visited the region to push for de-escalation.

Israeli Prime Minister Benjamin Netanyahu has claimed the United States is withholding weapons and implied this was slowing Israel's offensive in the southern Gaza city of Rafah, where fighting has exacerbated the already dire humanitarian situation for Palestinians.

President Joe Biden has delayed delivering certain heavy bombs since May over concerns about Israel's killing of civilians in Gaza. Yet the administration has gone to lengths to avoid any suggestion that Israeli forces have crossed a red line in the deepening Rafah invasion, which would trigger a more sweeping ban on arms transfers.

The Sudanese government has accused the United Arab Emirates of fueling the 14-month war in the African country by providing weapons to a rival paramilitary force. The UAE dismissed the allegation as "ludicrous," calling "a shameful abuse by one of the warring parties."

The clash came during a U.N. Security Council meeting at which Assistant Secretary-General Martha Pobee warned that atrocities are being committed along ethnic lines in Sudan's western Darfur region.

A bulk carrier sank days after an attack by Yemen's Houthi rebels believed to have killed one mariner on board, authorities said early Wednesday, the second ship sunk in the rebels' campaign.

The sinking of the Tutor in the Red Sea marks what appears to be a new escalation by the Iranian-backed Houthis in their campaign targeting shipping through the vital maritime corridor over the Israel-Hamas war in the Gaza Strip.

A Syrian army officer was killed Wednesday in an Israeli air strike in the country's south, the official SANA news agency reported, citing a military source.

"The Israeli enemy carried out an aggression using drones against two military positions of our armed forces in the provinces of Quneitra and Daraa," the agency said, adding the attack resulted in the death of the officer and material damage.

A senior Israeli negotiator told AFP that tens of hostages held by Hamas in Gaza are certainly alive and that Israel cannot accept halting the war until all captives are released in a deal.

Thousands of Israelis protested against Prime Minister Benjamin Netanyahu's government on Monday over the Gaza war and failure to negotiate the release of scores of hostages still held in the Palestinian territory.

Israel struck Gaza on Monday and witnesses reported blasts in the besieged territory's south, but fighting had largely subsided amid an army-declared "pause" to facilitate aid flows.

The relative calm came as Israel's Prime Minister Benjamin Netanyahu dissolved his war cabinet, reflecting Israel's political fractures.

Gaza saw its first day of relative calm in months Sunday, after Israel's military said it would "pause" fighting daily around a southern route to facilitate aid flows, following repeated U.N. warnings of famine in the Palestinian territory.

"Compared with the previous days, today, the first day of Eid al-Adha, is considered near calm and the calm has prevailed across all of Gaza," Mahmud Basal, spokesman for the civil defense agency in Hamas-ruled Gaza, told AFP.

President Joe Biden used his Eid al-Adha message to Muslims to advocate a U.S.-backed ceasefire deal in Gaza, saying Sunday it was the best way to help civilians suffering the "horrors of war between Hamas and Israel."