The committee, which monitors countries' adherence to the International Convention on the Rights of the Child, expressed its "outrage at the profound suffering of children" in the Israeli war in Gaza.
"Grave human rights violations against children are mounting by the minute in the Gaza Strip, and there are no winners in a war where thousands of children are killed," the committee said in a statement.
Since the start of the Israeli war on Gaza on 7 October, Israel has carried out a deadly and devastating campaign of airstrikes and bombardment that killed and injured thousands of Palestinians in the Gaza Strip.
The Palestinian health ministry in Gaza says nearly 8,800 people have been killed since the war with Israel erupted, while more than 22,000 people have been wounded.
The UN committee "strongly condemns the escalation of attacks by Israel against civilian targets in the Gaza Strip, which had resulted in the deaths of more than 3,500 children since 7 October.
"We also remain deeply concerned about children who continue to be held as hostages," it said.
"The committee calls for an end to the devastating harm being wreaked on children's lives in the occupied Palestinian territory. We add our voice to those calling for an immediate ceasefire. We urge the immediate release of child hostages, with their caregivers, as a first urgent phase towards the release of all hostages."
The independent committee's 18 members are independent human rights experts from around the world, who serve in a personal capacity.
They said there had been "devastating reports of acts that are forbidden by international humanitarian law, including maiming, injury, abduction, forcible displacement, deprivation of medical care, food, and water".
The committee said armed conflict harmed children first and foremost, and had lifelong effects on their physical and mental health, their development, and ultimately the enjoyment of all their rights.
Children are also harmed when they survive but lose parents and other family members and friends, and when they witness catastrophic events, the committee added.
They called on all parties to protect all children and provide them with the necessary medical and psychological support.
"The ceasefire should be the beginning of discussions aimed at establishing a just and lasting peace in the region so that all children can fully enjoy all their rights," the committee said.
*This story was edited by Ahram Online