UN Palestinian refugee agency chief Philippe Lazzarini said Friday that Israel "must stop its campaign against UNRWA" in an opinion article published by the New York Times.

"The war in Gaza has produced a blatant disregard for the mission of the United Nations, including outrageous attacks on (UNRWA) employees, facilities and operations," agency chief Lazzarini said.

"These attacks must stop and the world must act to hold the perpetrators accountable."

UNRWA, which coordinates nearly all aid to Gaza, has been in crisis since January, when Israel accused about a dozen of its 13,000 Gaza employees of being involved in the October 7 attack.

That prompted many governments, including top donor the United States, to abruptly suspend funding to the agency, threatening its efforts to deliver aid in Gaza, although several have since resumed payments.

An independent review of UNRWA, led by French former foreign minister Catherine Colonna, found some "neutrality-related issues" but said Israel had yet to provide evidence for its leading allegations.

"Israeli officials are not only threatening the work of our staff and mission, they are also delegitimising UNRWA by effectively characterising it as a terrorist organisation that fosters extremism and labelling UN leaders as terrorists who collude with Hamas," Lazzarini said.

He said the "assault on UNRWA has spread to (Israeli-annexed) east Jerusalem", where demonstrations outside the agency's compound have become common in recent months, and "increasingly dangerous, with at least two arson attacks".

UNRWA last week suspended food distribution in southern Gaza, including Rafah, after Israel launched an offensive in the city and seized the Rafah border crossing with Egypt.

The war was sparked by Hamas's attack on southern Israel, which resulted in the deaths of 1,189 people, mostly civilians, according to an AFP tally based on Israeli official figures.

Militants also took 252 hostages, 121 of whom remain in Gaza, including 37 the army says are dead.

Israel's retaliatory offensive has killed at least 36,284 people in Gaza, mostly civilians, according to the Hamas-run territory's health ministry.