GAZA/JERUSALEM — Dozens of people were killed in Israeli attacks on districts of Gaza City in the north of the Palestinian enclave on Saturday, as food continued to pile up at a Gaza crossing amid warnings from agencies that they are unable to deliver aid.

One Israeli strike on houses in Al-Shati, one of the Gaza Strip's eight historic refugee camps, killed 24 people, Ismail Al-Thawabta, director of the Hamas-run government media office, told Reuters. Another 18 Palestinians were killed in a strike on houses in the Al-Tuffah neighborhood.

The Israeli military issued a statement saying: "A short while ago, IDF fighter jets struck two Hamas military infrastructure sites in the area of Gaza City."

Hamas said the attacks targeted the civilian population and that the perpetrators "will pay the price for their violations against our people".

"People were going about their business" when, suddenly, "the whole area was wiped out" in an airstrike, said Abu Mahmud al-Kariri, a witness in Al-Shati.

The European Union's foreign affairs chief, Josep Borrell, on Saturday called for an "independent investigation" into the shelling that damaged the office of the International Committee of the Red Cross

Late on Friday, the committee said 22 dead and 45 wounded were taken to a Red Cross field hospital after shelling with "heavy caliber projectiles" near its southern Gaza office.

Gaza's health ministry blamed the shelling on Israel.

The Israel military said on Saturday that an initial inquiry found "there was no direct attack carried out by the IDF against a Red Cross facility", but that the matter was being looked into.

The conflict has led to dire humanitarian conditions in the Gaza Strip and repeated warnings by the United Nations of famine.

Desperation among Gaza's 2.4 million people has increased as fighting rages, bringing warnings from agencies that they are unable to deliver aid.

"The breakdown of public order and safety is increasingly endangering humanitarian workers and operations in Gaza," the UN Office for the Coordination of Humanitarian Affairs said on Friday.

With civil order breaking down in Gaza, the UN says it has been unable to pick up any supplies from Kerem Shalom since Tuesday, leaving crucial aid in limbo.

A deputy UN spokesman said last week that the crossing "is operating with limited functionality, including because of fighting in the area".

Tel Aviv protests

On Saturday, Israel's Prime Minister Benjamin Netanyahu faced what organizers said was the biggest anti-government protest since the conflict began.

Tens of thousands rallied in Tel Aviv. One demonstrator's sign accused Netanyahu of being an "Enemy of Israel".

Supporters and families of the Gaza hostages also rallied, holding their pictures aloft.

Netanyahu said on Sunday that a dispute with the United States over weapons delays relating to the Gaza conflict would be resolved soon.

Israel's Defense Minister Yoav Gallant flew to Washington to discuss the next phase of the war and escalating hostilities on the border with Lebanon.

Exchanges of fire across the Lebanese border between Israel and Hezbollah have also escalated, raising fears of wider conflict.

On Saturday a security source said a leader of the Lebanese group Jamaa Islamiya was killed in an Israeli strike on a vehicle in eastern Lebanon.

Hezbollah said it had targeted a military position in northern Israel "with an attack drone" in response to the killing of a commander of the Jamaa Islamiya group.

The UN Secretary-General Antonio Guterres said cross-border hostilities must not turn Lebanon into "another Gaza".

"One rash move — one miscalculation — could trigger a catastrophe that goes far beyond the border and, frankly, beyond imagination."

Violence has also soared in the Israeli-occupied West Bank.

Israeli troops tied a wounded Palestinian man to a military vehicle during a raid in the city of Jenin on Saturday, the army said on Sunday, acknowledging that soldiers had violated operational procedures.

Footage of the incident on the internet shows a Jenin resident strapped to the hood of a military jeep as it passes through a narrow alley.

"The incident will be investigated and dealt with accordingly," the military said, adding that the wounded man was transferred to the Palestinian Red Crescent for treatment.

Agencies via Xinhua