By Nidal al-Mughrabi and Olivia Le Poidevin

CAIRO/GENEVA (Reuters) -Israeli fire killed at least 44 Palestinians in Gaza on Friday, many who were seeking food aid, local officials said, while the United Nations' children's agency said the scarcity of drinking water was at a crisis point.

At least 25 people awaiting aid trucks were killed by Israeli action south of Netzarim in central Gaza, the Hamas-run local health authority said.

The Gaza Humanitarian Foundation, which runs a month-old U.S.-backed food distribution system, operates an aid site there, and aid trucks from other organisations including the U.N. also move through the area.

Commenting on the incident, the Israeli military said troops fired warning shots at suspected militants who advanced in a crowd towards them. Israeli aircraft then fired a missile and "eliminated the suspects," it said in a statement.

The military said it was aware that people other than the suspected militants were hurt and it was conducting a review. GHF said the incident did not occur at or near its distribution location.

Separately, Gaza medics said at least 19 other people were killed in Israeli military strikes across the enclave on Friday, including 12 people in a house in Deir Al-Balah in central Gaza Strip.

Meanwhile the U.N.'s children's agency UNICEF warned in Geneva that a shortage of fuel to operate wells and desalination plants in Gaza meant the enclave "is facing what would amount to a man-made drought."

"Children will begin to die of thirst ... Just 40% of drinking water production facilities remain functional," UNICEF spokesperson James Elder told reporters. "We are way below emergency standards in terms of drinking water."

UNICEF also reported a 50% increase in children aged six months to 5 years admitted for treatment of malnutrition from April to May in Gaza, and half a million people going hungry.

FOOD AID

In a statement, Hamas, which says Israel uses hunger as a weapon against Gaza's civiians, accused Israel of systematically targeting Palestinians seeking food. Israel denies this and contends Hamas steals aid, which the group denies.

In recent weeks, Israeli forces have repeatedly opened fire on Palestinians gathered at aid distribution points, resulting in dozens of civilian deaths and injuries. Humanitarian groups say the Gaza Humanitarian Foundation system forces people to risk their lives by entering combat zones to access food.

Israel has said its actions were necessary to control crowds that posed a threat to its troops or to prevent breaches of restricted zones. But witnesses and human rights groups say many of the shootings appeared unprovoked and occurred without warning.

UNICEF said GHF was "making a desperate situation worse". GHF said in a statement on Thursday it had so far distributed nearly three million meals across three of its aid sites without incident.

The Red Cross said the "vast majority" of patients that arrived at its Gaza field hospital during mass casualty incidents since the GHF aid system launched on May 27 had reported that they were wounded while trying to access aid at or around distribution points.

The Gaza war was triggered when Palestinian Hamas militants attacked Israel on October 7, 2023, killing 1,200 people and taking 251 hostages, according to Israeli tallies.

Israel's subsequent military assault on Gaza has killed nearly 55,700 Palestinians, according to Gaza's health ministry, while displacing almost the entire population of more than 2 million and causing a hunger crisis.

(Additional reporting by Estelle Shirbon and Emma Farge in Geneva; Editing by Gareth Jones and Andrew Heavens)