By Pauline Lockwood, Hira Humayun, and Ibrahim Dahman, CNN

(CNN) — Nearly a hundred aid trucks were looted in southern Gaza on Saturday in whatUNRWA, the UN agency for Palestinian refugees, has described as “one of the worst” incidents of its kind.

Of the 109 trucks carrying food supplies for UNRWA and the World Food Programme from the Kerem Shalom crossing into Gaza, 97 trucks were “lost” in the looting, UNRWA told CNN in a statement Monday.

Drivers were forced to unload trucks at gun point, aid workers were injured, and vehicles were damaged extensively, it said.

UNRWA did not identify the perpetrators of the looting, but blamed the “collapse of law and order” and the “approach of the Israeli authorities” for creating a “perilous environment.”

It said the challenges involved in delivering aid to Gaza had become “increasingly insurmountable,” with “trucks frequently delayed at various holding points, often looted, and subjected to escalating attacks.”

“Well, we have been warning for a long time about the total breakdown of civil order; (until) four or five months ago, we still had local capacity, people who were escorting the convoys. This has completely gone,” UNRWA chief Philippe Lazzarini told a press conference in Geneva on Monday.

CNN has reached out to Israeli authorities on the matter but has not yet heard back.

In a report Monday that cited Gaza’s interior ministry, the Hamas-run Al-Aqsa TV channel claimed Gaza security forces had killed more than 20 people involved in looting aid trucks, though it did not specifically mention Saturday’s incident.

The National and Islamic Forces, a coalition of Palestinian groups, commended the ministry’s actions against the looters, who it referred to as “criminal thieves who disrupt the security of our internal front and steal the livelihoods, bread, and medicine of our citizens.”

Worsening shortages

The attack on the convoy – the worst of its kind “in terms of volume”, according to UN Secretary-General Stéphane Dujarric – comes amid warnings by the UN that already severe shortages of food and aid in Gaza will worsen without immediate intervention.

Civilians fleeing northern Gaza after weeks of intense Israeli military operations have told of a chronic lack of food and people dying of hunger, while aid agencies have warned that the area is on the brink of famine.

On Thursday, a UN Special Committee report alleged Israel was using starvation as a method of war – an allegation denied by COGAT, the Israeli agency that approves aid shipments into Gaza.

Israel insists however that the number of aid trucks entering Gaza has risen and that it is “working tirelessly” to get aid into the enclave. The US State Department last week assessed it was not blocking aid – though it said improvements were needed.

The attack on the convoy also comes amid a backdrop of deteriorating relations between Israel and UNRWA. The agency’s ability to deliver aid to Gaza took a hit last month when Israel’s parliament voted to ban it, in a move that is expected to severely restrict its operations in territories Israel occupies, including the West Bank and East Jerusalem.

The new law requires all contact between Israeli officials and the UN agency to cease by the end of January.

Israel claims UNRWA has forced it to act, alleging that some of its employees are affiliated with Hamas and that its schools teach hate against Israel. UNRWA has repeatedly denied these accusations.

At the press conference in Geneva, Lazzarini spoke of the UN’s concerns over the new law, warning there was no other agency that could replace UNRWA’s role in helping the Palestinians.

“Our staff in the region is deeply, deeply concerned, anxious, worried about what might happen,” he said.

Lazzarini also told the conference of an incident last week in which he said a female UNRWA worker had been searched at her home by IDF soldiers.

“When they realized that she is working for UNRWA, basically, they told her, ‘How come you work for a terrorist organization?’” Lazzarini said, adding that the soldiers asked her for access to all the data in her computer, brought her in for interrogation for a few hours, and handcuffed her to a post. CNN has reached out to the IDF about the incident.

Heavy toll on civilians

Meanwhile, Israeli strikes in Gaza continue to take a heavy toll on civilians.

On Monday, Israeli airstrikes killed at least 50 people, including 17 members of a single family, according to the local health ministry.

Most of the dead were killed in on northern Gaza, including the 17 family members who died in the city of Beit Lahiya, the ministry’s general director Dr. Munir Al-Bursh told CNN.

He said the 17 were family members of Hani Badran, a cardiologist who was working at the city’s Kamal Adwan hospital at the time of the strike that killed them.

A local journalist who spoke to the cardiologist told CNN that Badran’s children had been killed alongside his sister, her husband and their children. Among the killed children was his sister’s weeks-old newborn, who Badran had delivered and whose birth he had intended to register on Monday, he said.

The director of the hospital, Dr. Hussam Abu Safiya, said that everyone in Badran’s home at the time had been killed.

Safiya said the hospital itself had also been attacked.

“This scene is now being repeated almost constantly. Very violent targeting, with shells from tanks,” Safiya said.

He said patients were filled with “fear and horror,” adding “we are now pleading to the world. This killing machine must be stopped, the bombing must be stopped.”

CNN has reached out to the Israeli military for comment on the hospital attack. It has previously said it was operating “against terrorist infrastructure and operatives” in Beit Lahiya.