GAZA/JERUSALEM – Fears over the risk of the Israel-Hamas war mushrooming into a wider Middle East conflict rose on Sunday, with Washington warning of a significant risk to United States’ interests in the region as ally Israel pounded Gaza and clashes on its border with Lebanon intensified.

Gaza’s health ministry said 266 Palestinians, including 117 children, had been killed by Israeli air strikes in the past 24 hours in the enclave, to which Israel laid “total siege” after a deadly mass infiltration into Israel by Hamas gunmen on Oct 7.

In neighbouring Syria – where Hamas’ main regional backer, Iran, has a military presence – Israeli missiles hit Damascus and Aleppo international airports early on Sunday, putting both out of service and killing two workers, Syrian state media said.

Along Israel’s northern border with Lebanon, the Iran-backed Hezbollah has clashed with Israeli forces in support of Hamas in the deadliest escalation of frontier violence since an Israel-Hezbollah war in 2006.

Hezbollah said four fighters were killed in heavy exchanges of fire on Sunday and another died of wounds received earlier, raising to 24 the number of its members killed since Oct 7.

Lebanese security sources said 11 fighters with Palestinian militant groups in Lebanon had also been killed in the volatile border region, alongside four civilians.

At least five Israeli soldiers and one civilian have been killed on Israel’s side of the frontier, according to Israeli military reports.

With violence around its heavily guarded borders increasing, Israel on Sunday added 14 communities close to Lebanon and Syria to its evacuation contingency plan in the north of the country.

US Defence Secretary Lloyd Austin said Washington would send more military assets to the Middle East to support Israel and strengthen the US defence posture in the region following “recent escalations by Iran and its proxy forces” – a reference to Hezbollah and Palestinian Islamist militants.

Mr Austin told ABC’s This Week programme on Sunday: “We’re concerned about potential escalation. In fact, what we’re seeing... is the prospect of a significant escalation of attacks on our troops and our people throughout the region.

“If any group or any country is looking to widen this conflict and take advantage of this very unfortunate situation... our advice is: don’t,” he added.

Washington has already deployed a significant amount of naval power to the Middle East in recent weeks, including two aircraft carriers, support ships and about 2,000 marines, to help deter attacks by Iran-affiliated forces that could inflame the wider region.

Mr Austin said a terminal high-altitude area defence (Thaad) system and additional Patriot air defence missile system battalions will be sent to the region, and more troops will be put on standby.

Iranian security officials told Reuters that Iran’s strategy was for Middle East proxies like Hezbollah to pursue limited strikes on Israeli and US targets but avoid a major escalation that would draw in Teheran, a high-wire act for the Islamic republic.

Israel unleashed an aerial blitz on Gaza, which lies to its south-west, after Hamas militants breached the border and carried out a shock rampage through nearby communities, killing 1,400 people, mainly civilians, and taking 212 hostages back to Gaza.

Gaza’s health ministry said on Sunday that Israel’s air and missile strikes in retaliation had killed at least 4,741 and wounded 15,898, with more than a million of the tiny territory’s 2.3 million people displaced.

Israel has amassed tanks and troops near the fenced border around Gaza for a planned ground invasion aiming to annihilate Hamas, after several inconclusive wars dating to its seizure of power there in 2007, after Israel ended a 38-year occupation.

Elaborating on Israel’s strategy in remarks to Fox TV on Sunday, military spokesman Jonathan Conricus said it was “to have a weakened, tired and dislocated Hamas in preparation for our next stage of military operations”.

“Our working assumption,” he said, “is that Hamas has prepared the battlefield, that there are various dimensions of warfare ready for us – specifically tunnels – and that Hamas, at least in the first and the intermediate stages, will fight and will inflict heavy casualties on (Israeli forces).”

Hamas’ armed wing said it had fired rockets at Tel Aviv on Sunday. There was no immediate word of damage or casualties.

With Israel keeping up daily bombardments that have laid waste to swathes of the densely populated enclave, Palestinians said they received renewed Israeli military warnings to move from Gaza’s north to the south to avoid the deadliest theatre of the war.

They said military leaflets dropped on the narrow territory, just 45km long, contained the added warning that they could be identified as sympathisers with a “terrorist organisation” if they stayed put.

“For your own safety, move southward. We will continue to attack in the area of Gaza City and increase attacks,” Israeli military spokesman Daniel Hagari said.

Gaza’s health ministry said that most of the dead from air strikes over the past 24 hours were in the area’s south. Israel says it is targeting only militants and that they often use residential buildings as cover.

Deprived of electricity and water under Israeli siege, Gazans in the southern town of Khan Younis said they were struggling to feed their children, forming long queues to get bread made scarcer by power blackouts and a lack of flour.

“We are suffering extremely, waiting since dawn to get bread. If this continues for two more days, it will be catastrophic,” said Mr Saleh Skafi, a father of four from north Gaza now sheltering in Khan Younis.

“The children here are starving. The situation is tragic.”

The first humanitarian aid convoy allowed into Gaza since war erupted arrived through its southern Rafah border crossing from Egypt on Saturday after days of tortuous negotiations.

The United Nations said the 20-truck convoy brought life-saving supplies and some food.

A second convoy of 17 trucks loaded with medical and food supplies entered the Egyptian side of the Rafah crossing on Sunday and was being inspected before proceeding into Gaza, said security and humanitarian sources.

But the UN humanitarian office said the volume of goods that entered on Saturday was just 4 per cent of the daily average of imports into Gaza before the hostilities and a fraction of what was needed, with the enclave running out of food, water, medicines and fuel.

Moreover, Israel has refused to allow fuel in as part of aid shipments for fear that it could end up in Hamas’ hands.

Mr Philippe Lazzarini, head of the UN agency for Palestinian refugees UNRWA, said: “Without fuel, the humanitarian response will stop. There will be no water, no functioning hospitals and bakeries. This cannot and should not happen.” REUTERS