GAZA CITY — Relief operations in Gaza may be forced to halt by Wednesday night if no fuel is delivered to the territory, the United Nations Relief and Works Agency (UNRWA) said.

Vital fuel supplies needed to run hospitals, pump and desalinate water and power bakeries are on the verge of running out, with the main aid agency in Gaza warning the deep humanitarian crisis is getting worse by the hour.

“If we do not get fuel urgently, we will be forced to halt our operations in the #GazaStrip as of tomorrow night,” UNRWA wrote on X, formerly Twitter on Tuesday. "Fuel deliveries must be let in to ensure people have clean drinking water, hospitals can remain open and life-saving aid operations can continue," UNRWA also said.

Nearly 600,000 internally displaced people are sheltering in 150 UNRWA facilities across Gaza, the agency said on Wednesday, adding that the shelters are four times over their capacity.

At least 40 of its installations have been impacted and many others are sleeping on the streets.

Without fuel, water cannot be pumped or desalinated, which has left people in Gaza forced to drink dirty, salty water. Generators that power hospitals – for incubators, ventilators and dialysis machines as well as to sterilize surgical equipment – will also come to a stop.

Gaza needs at least 160,000 liters (42,267 gallons) of fuel a day for basic necessities, UNRWA spokesperson Juliette Touma said.

Israel is stopping new supplies of fuel reaching Gaza because it says Hamas is stockpiling existing supplies. This contradicts earlier comments from the IDF chief of staff, who said efforts would be made to provide access to fuel in Gaza, but that the IDF would "not allow" the fuel to reach Hamas.

Hospitals shutting down

Six hospitals in Gaza have already been forced to close due to a lack of fuel since the start of Israel's full siege of the territory two weeks ago, according to the World Health Organization on Tuesday.

Vulnerable patients – among them 1,000 patients dependent on dialysis and 130 premature babies – are at risk of dying amid power cuts.

Gaza’s largest hospital will become a “mass grave” if it runs out of fuel, a British-Palestinian doctor working there said Tuesday.

“The real question is, is there anything left of a hospital when there’s no electricity? And my answer is no. Effectively, Shifa Hospital will become a mass grave if it runs out of electricity,” Dr. Ghassan Abu-Sittah told CNN’s John Vause, adding there are currently 150 patients on ventilators with doctors unable to run operating theatres and anesthetic machines due to the shortages.

Only eight out of the 20 aid trucks that were originally scheduled to enter Gaza through the Rafah crossing went through on Tuesday, a spokesperson for UNRWA said. No specific reason was given on why the other 12 didn’t make it through the crossing. Part of the convoy that did pass through delivered five trucks loaded with water, two trucks loaded with food and one truck loaded with medicine, said the Palestine Red Crescent.

Gaza normally receives 455 aid trucks per day, according to the UN. A total of 62 trucks in four convoys entered Gaza since October 21, which is about 1% of what used to go into the territory daily, Juliette Touma, UNRWA communications director told CNN on Wednesday. — CNN