The situation in Gaza is "beyond catastrophic" with casualties mounting along aid convoy routes and in shelters as Israel continues to bar many medics, UN humanitarians said on Wednesday in a press release.

The UN Office for the Coordination of Humanitarian Affairs (OCHA) said that more people are being killed and injured along convoy routes or where they are staying.

"Hospitals are overstretched," and patients lying on the floor or in the streets are suffering while "beds, medical supplies and equipment are severely lacking," OCHA said, adding that emergency medical teams were denied entry into Gaza again on Tuesday.

According to the World Health Organization, more than 100 health professionals, including surgeons and other specialized medical staff, have been barred from entering Gaza since March.

OCHA said that a limited number of trucks carrying commercial goods were reportedly allowed entry into Gaza on Tuesday.

The office said that initial reports from its ground partners indicate that the items included rice, sugar and vegetables, but they are still following up to obtain more clarity on it.

Sugar remains one of the most expensive items in the market in Gaza, since "a 2-ounce (57 grams) bag costs some 170 U.S. dollars," said OCHA. "Eggs, poultry and meat have disappeared from the market."

OCHA said that the Ministry of Health in Gaza reported five new malnutrition-related deaths in the past 24 hours, bringing the total to about 200 deaths, half of whom were children.

The office said the limited availability of fuel continues to impact life-saving operations.

"In the past two days, the United Nations collected some 300,000 liters from the Kerem Shalom (Karem Abu Salem) crossing," but it is far less than what is needed to sustain operations, OCHA said.

The office said benzene, which powers emergency vehicles, runs generators and water and sanitation systems, reached very low levels, with hardly any entering Gaza during the past 10 days.

UN agencies and international nongovernmental organizations (NGOs) warned that unless urgent action is taken, most international NGOs partners could be de-registered in the coming months due to a recent Israeli policy, said OCHA.

They called on Israeli authorities to rescind the requirement, which obliges them to share sensitive personal information about their Palestinian employees in Gaza or face termination of their humanitarian operations, said OCHA.

That would force them to withdraw all international staff and prevent them from providing critical, life-saving humanitarian assistance to the Palestinians, according to the office.