More than a year into Israel's war against Hamas in the besieged Palestinian territory "children continue to suffer unspeakable daily harm", said James Elder, spokesman for the United Nations children's agency UNICEF.

"Gaza is the real-world embodiment of hell on Earth for its one million children," he told reporters in Geneva. "And it's getting worse, day by day."

Since Hamas's deadly Oct. 7 attack inside Israel, which sparked the war, "conservative" estimates put the death toll among children in Gaza at over 14,100, Elder said.

That means that "on a conservative measure, around 35 to 40 girls and boys are killed every day in Gaza, since Oct. 7", he said.

Elder said the numbers, provided by authorities in Gaza, who put the total death toll at over 42,400, were unfortunately trustworthy.

"There are many, many more under the rubble," he added.

And those who have survived the daily airstrikes and military operations have often faced harrowing conditions, he said. Children were being repeatedly displaced by violence and frequent evacuation orders even as "deprivation grips all of Gaza".

"Where would children and their families go? They are not safe in schools and shelters. They are not safe in hospitals. And they are certainly not safe in overcrowded camp sites," he said.

Elder described the experience of a seven-year-old girl named Qamar, who was struck in the foot during an attack on Jabaliya camp in northern Gaza.

Taken to a hospital that was then placed under a 20-day siege, she could not be moved or get the treatment she needed for her growing infection, and her leg was amputated.

"In any vaguely normal situation, this little girl's leg would never have needed to be amputated," said Elder.

Faced with fresh evacuation orders from Israel, the girl, her mother and her sister, who was also injured, were forced to move south, on foot.

"They now live in a ripped tent, surrounded by stagnant water," Elder said, adding that Qamar was "of course deeply traumatised", and without access to prosthetics.

UNICEF had already warned that Gaza had become "a graveyard for thousands of children" a year ago, he said.

Last December, the agency had declared Gaza "the most dangerous place in the world to be a child".

"Day after day, for more than a year now, that brutal evidence-based reality is reinforced," Elder added, describing a feeling of "deja vu, but with even darker shadows".

"If this level of horror doesn't stir our humanity and drive us to act, then whatever will?"