The Gaza Strip has become a graveyard for thousands of children, the United Nations said Tuesday, as it feared the prospect of more dying of dehydration.
Israel has heavily bombarded Gaza since Hamas gunmen stormed across the border on October 7, killing 1,400 people, mostly civilians, and kidnapping at least 240 others, according to Israeli officials.
The health ministry in the Hamas-run Gaza Strip said the strikes have killed more than 8,500 people, mainly civilians.
The UN children's agency UNICEF said there was a risk that the number of child deaths directly from bombardment could become eclipsed.
"Our gravest fears about the reported numbers of children killed becoming dozens, then hundreds, and ultimately thousands were realised in just a fortnight," UNICEF spokesman James Elder said in a statement.
"The numbers are appalling; reportedly more than 3,450 children killed; staggeringly this rises significantly every day."
"Gaza has become a graveyard for thousands of children. It's a living hell for everyone else."
He said the more than one million children living in the Gaza Strip were also suffering from a lack of clean water.
"Gaza's water production capacity is a mere five percent of its usual daily output. Child deaths -- particularly infants -- to dehydration are a growing threat," he said.
UNICEF is calling for an immediate humanitarian ceasefire, with all access crossings into Gaza opened for the safe, sustained and unimpeded access of humanitarian aid, including water, food, medical supplies, and fuel.
"And if there is no ceasefire, no water, no medicine, and no release of abducted children? Then we hurtle towards even greater horrors afflicting innocent children," said Elder.
"There are certainly children who are dying who have been impacted by the bombardment but should have had their lives saved," Elder told reporters in Geneva, via video-link.
He said that without greater humanitarian access into the Gaza Strip, "then the deaths from the attacks, they could absolutely be the tip of the iceberg".
Elder said that according to figures from health faculties in the Hamas-run Gaza Strip, some 940 children were missing.
UN humanitarian agency spokesman Jens Laerke added: "It's almost unbearable to think about children buried under rubble, but (with) very little opportunity or possibility for getting them out."
The World Health Organization said people in Gaza were dying not just from direct bombardment.
"We have 130 premature infants that are dependent on incubators, of which 61 percent approximately are in the north," said WHO spokesman Christian Lindmeier.
"It's an imminent public health catastrophe that looms with the mass displacement, the overcrowding, and the damage to water and sanitation infrastructure."
UN chief 'deeply alarmed' by escalation of Israel-Hamas conflict
The United Nations chief said Tuesday he was "deeply alarmed by the intensification of the conflict between Israel and Hamas" as fierce fighting raged in Gaza.
The escalation includes "ground operations by the Israel Defense Forces accompanied by intense air strikes, and the continued rocket fire towards Israel from Gaza," UN Secretary-General Antonio Guterres said in a statement.
"Civilians have borne the brunt of the current fighting from the outset," he said.
"I repeat my utter condemnation of the acts of terror perpetrated by Hamas on 7 October. There is never any justification for the killing, injuring and abduction of civilians. I appeal for the immediate and unconditional release of those civilians held hostage by Hamas.
"I condemn the killing of civilians in Gaza and I am dismayed by reports that two-thirds of those who have been killed are women and children."
Guterres also underlined his fears "about the risk of a dangerous escalation beyond Gaza."