The World Health Organization (WHO) director-general said on Wednesday that Gaza is facing man-made mass starvation, citing the ongoing Israeli blockade and severe restrictions on humanitarian aid deliveries.

"I don't know what you would call it other than mass starvation, and it's man-made, and that's very clear," said WHO chief Tedros Adhanom Ghebreyesus at a virtual press conference. "This is because of (the) blockade."

Tedros's comments followed an appeal by more than 100 aid agencies warning of a deepening hunger crisis in Gaza, where tonnes of food, clean water and medical supplies remain stuck outside the enclave.

Gaza's food supplies have run out, aid agencies say, since Israel imposed a full blockade in March as part of its war against Palestinian militant group Hamas. Although the blockade was eased in May, international organizations say only a limited flow of aid is reaching Gaza's population of 2.2 million.

Israel maintains that the restrictions are necessary to prevent aid from being diverted to militants, and says it has facilitated the delivery of sufficient food. It has repeatedly blamed Hamas for the suffering inside Gaza.

Surging hunger deaths

The Gaza health authorities said on Wednesday that 10 more people had died overnight from starvation, bringing the total to 111 since the conflict began, most of them in recent weeks as hunger spreads.

The WHO said at least 21 child deaths from malnutrition have been reported so far this year, but stressed the real toll is likely far higher. Centers for treating malnutrition are full and lack emergency supplies, officials said.

Tedros added that the United Nations and its humanitarian partners were unable to deliver any food between March and May for nearly 80 days, and that aid deliveries since then remain insufficient to meet needs.

According to the WHO, screenings show that roughly 10 percent of the population in Gaza is suffering from either moderate or severe malnutrition, including up to 20 percent of pregnant women.

"In July alone, 5,100 children have been admitted to malnutrition programs, including 800 who were severely emaciated," said Rik Peeperkorn, the WHO's representative for the occupied Palestinian territories.

Aid operations under severe strain

Access to supplies for distribution to hungry Gazans and security risks for aid workers are putting relief operations under severe strain, the UN Office for the Coordination of Humanitarian Affairs (OCHA) said on Wednesday.

Relief workers face significant security risks. Supply crossings remain unreliable and critical supplies are routinely delayed or blocked. The amount of aid that has been entering Gaza is a trickle compared to the immense needs, the OCHA said.

"Israel must enable safe and unimpeded aid delivery, allow the entry of critical equipment and fuel, open all crossings, and restore movement along key supply routes," the OCHA added.

It warned that the hunger crisis in Gaza has never been so dire, with aid organizations reporting that as mass starvation spreads across the Gaza Strip, aid workers and those they serve are wasting away.

The office said its partners have reported that aid workers are fainting from hunger and exhaustion. Despite catastrophic conditions, aid workers continue to deliver life-saving assistance, wherever and whenever possible.

The OCHA said that to sustain operations, including nutrition programs, the Israeli authorities must facilitate the delivery of much more aid into and across all areas of the Gaza Strip without delay.

It added that hospitals in Gaza are overwhelmed and cannot cope with the influx of patients, including those injured by hostilities, due to a lack of supplies and fuel.

The office said that local health authorities reported that in the past few days, several of their health facilities were shut down due to lack of fuel. More hospitals, including Al Shifa, are at risk of shutting down within the next few days.

(With input from agencies)