The UN children's agency UNICEF said that at least 60 boys and 40 girls had been killed in the Israeli-occupied Palestinian territory since early October.

"More than 100 children have been killed in Gaza since the ceasefire," UNICEF spokesman James Elder told reporters in Geneva.

"That's roughly a girl or a boy killed here every day during a ceasefire," he said, speaking from Gaza City.

"These children are killed from airstrikes, drone strikes, including suicide drones. They're killed from tank shelling. They're killed from live ammunition. They're killed from quad copters.

"We are at 100 -- no doubt," he said, adding that the true number was likely higher.

"A ceasefire that slows the bombs is progress but one that still buries children is not enough."

AFP has sought a response from the Israeli military.

An official at Gaza's health ministry, which maintains casualty records, has reported a higher figure of 165 children killed during the tenuous ceasefire, out of a total 442 fatalities.

"Additionally, seven children have died from exposure to cold since the beginning of this year," Zaher Al-Wahidi, Director of the Computer Department at the Ministry of Health, told AFP.

Elder stressed that the ongoing Israeli attacks came after more than two years of war which has "left life for Gaza's children unimaginably hard".

"They still live in fear. The psychological damage remains untreated, and it's becoming deeper and harder to heal the longer this goes on," he said.

In November, authorities in Gaza said more than 70,000 people had been killed there since the beginning of the war waged by Israel in response to Hamas's October 7, 2023, attack on Israel.

Nearly 80 percent of buildings in Gaza have been destroyed or damaged in the relentless air and ground offensive, according to UN data.

On January 1, Israel suspended 37 international aid agencies from accessing the Gaza Strip, despite what the UN said at the time was an "outrageous" move.

"Blocking international NGOs, blocking any humanitarian aid... that means blocking life-saving assistance," Elder stressed on Monday.

While UNICEF had managed to significantly increase aid entering the densely populated strip since October, he stressed: "You need partners on the ground, and it (the aid) still doesn't meet the need."

"It's impossible to overstate just how much still is required to be done here."

He also insisted: "When you've got key NGOs banned from delivering humanitarian aid and from bearing witness, and when foreign journalists are barred" it begs the question if the aim is "restricting scrutiny of suffering of children".